The Open Archives Initiative Protocol for Metadata Harvesting
	Protocol Version 1.1 of 2001-07-02 Document Version 2001-06-20 http://www.openarchives.org/OAI/openarchivesprotocol.htm Previous version: Protocol Version 1.0 of 2001-01-21 Instructions for migrating from Version 1.0 to 1.1

Editors

Herbert Van de Sompel <herbertv@cs.cornell.edu> -- Cornell University - Computer Science
Carl Lagoze <lagoze@cs.cornell.edu> -- Cornell University - Computer Science

Table of Contents

Introduction
Definitions and Concepts
    Repository
    Record
    Unique Identifier
    Datestamp
    Set
Protocol Features
    HTTP embedding of OAI requests
        HTTP Request Format
        HTTP Response Format
    Dates and Times
    Metadata Prefix and Metadata Schema
    Flow Control
Protocol Requests and Responses
    GetRecord
    Identify
    ListIdentifiers
    ListMetadataFormats
    ListRecords
    ListSets
Appendix 1: Sample XML Schema for metadata formats
    Dublin Core
    rfc1807
    oai_marc
Appendix 2: Sample XML Schema for description part of reply to Identify request
   description for repositories that share the OAI format for unique identifiers of records
   description for repositories in the e-print community
Acknowledgements

The goal of the Open Archives Initiative Protocol for Metadata Harvesting (referred to as the OAI protocol in the remainder of this document) is to supply and promote an application-independent interoperability framework that can be used by a variety of communities who are engaged in publishing content on the Web.   The OAI protocol described in this document permits metadata harvesting. The result is an interoperability framework with two classes of participants:

• Data Providers administer systems that support the OAI protocol as a means of exposing metadata about the content in their systems;
• Service Providers issue OAI protocol requests to the systems of data providers and use the returned metadata as a basis for building value-added services.

A repository is a network accessible server to which OAI protocol requests, embedded in HTTP, can be submitted.  The OAI protocol provides access to metadata from OAI-compliant repositories.  This metadata is output in the form of a record.  A record is the result of a protocol request issued to the repository to disseminate metadata from an item. An item can be considered a constituent of the repository.  The  nature of an item -- for example, what type of metadata is actually stored in the item, what type is derived on-the-fly,  and whether the item includes the "full content" described by the metadata -- is outside the scope of the OAI protocol.  All uses of the term repository in the remainder of this document should be interpreted as an OAI-compliant repository.

• header -- information that is common to all records and that is necessary for the harvesting process. This information is independent of the metadata format disseminated in the record. The header consists of two parts:
  • the unique identifier -- the key for extracting metadata from an item in a repository;
  • the datestamp -- the date of creation, deletion, or latest date of modification of an item, the effect of which is a change in the metadata of a record disseminated from that item.
• metadata -- a single manifestation of the metadata from an item.  The OAI protocol supports multiple manifestations (formats) of metadata for any single item.  At a minimum, repositories must be able to return records with metadata expressed in the Dublin Core format, without any qualification. Optionally, a repository may also be capable of disseminating other formats of metadata.  The specific manifestation that should be returned in a record is specified by means of an argument -- the metadata prefix -- in the GetRecord or ListRecords protocol request that produces the record.  The ListMetadataFormats protocol request returns the list of metadata formats available from a repository, or from a specific item (which can be specified as an argument to the ListMetadataFormats service request).
• about -- an optional container to hold data about the metadata part of the record. Typically, the about container could be used to hold rights information regarding the metadata part of the record, terms and conditions for usage of the metadata part of the record, etc. The internal structure of the about container is not defined by the protocol. It is left to individual communities to decide on its syntax and semantics.

The example shows a record and its components:

• the header part with:
  • a unique identifier equal to oai:arXiv:quant-ph/9901001;
  • a datestamp equal to 1999-01-01;
• the metadata part expressed in unqualified Dublin Core.  Note that the root element within the metadata part includes three attributes:    
  •  xmlns -- the value of which is the namespace URI (as defined by the XML namespace specification) of the metadata that follows in this part.
  • xmlns:xsi -- the value of which must always be the URI shown in the example, which is the namespace URI for XML schema.
  • xsi:schemaLocation -- the value of which is a pair, the first part is the namespace URI (as defined by the XML namespace specification) of the metadata that follows in this part, and the second part is the URL of the XML schema for validation of the metadata.  
• the about part of the record which uses a -- fictional -- eprints-about.xsd schema as a means to express properties of the metadata part of the record.  Note that the root element within the about part includes three attributes:    
  •  xmlns -- the value of which is the namespace URI (as defined by the XML namespace specification) of the XML elements that follow in this part.
  • xmlns:xsi -- the value of which must always be the URI shown in the example, which is the namespace URI for XML schema.
  • xsi:schemaLocation -- the value of which is a pair, the first part is the namespace URI (as defined by the XML namespace specification) of the elements that follow in this part, and the second part is the URL of the XML schema for validation of the about part. 

  <header>

   <identifier>oai:arXiv:quant-ph/9901001</identifier>

   <datestamp>1999-01-01</datestamp>

  </header>

  <metadata>

   <dc xmlns="http://purl.org/dc/elements/1.1/" 

       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

       xsi:schemaLocation="http://purl.org/dc/elements/1.1/

                           http://www.openarchives.org/OAI/1.1/dc.xsd">

    <title>Quantum slow motion</title>

    <creator>Hug, M.</creator>

    <creator>Milburn, G. J.</creator>

    <description>We simulate the center of mass motion of cold atoms in a 
     standing, amplitude modulated, laser field as an example of a system
     that has a classical mixed phase-space.</description>

    <date>1999-01-01</date>

    <type>e-print</type>

    <identifier>http://arXiv.org/abs/quant-ph/9901001</identifier>

   </dc>

  </metadata>

  <about>

   <ea xmlns="http://www.arXiv.org/eprints-about"

       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

       xsi:schemaLocation="http://www.arXiv.org/eprints-about

                           http://www.arXiv.org/eprints-about.xsd">

    <archive>The Los Alamos arXiv</archive>

    <usage>Metadata may be used without restrictions as long as the OAI 
     identifier remains attached to it.</usage>

   </ea>

  </about>

The protocol supports the notion of a deleted record, which may be used by repositories as follows.  When returning a harvested record or identifier of a record, the  ListRecords and ListIdentifiers service requests may indicate a status of "deleted".  This status means that an item has been deleted and therefore no record can be disseminated from it.   The length of time that a given repository keeps track of deleted items is not defined by the protocol.  Therefore, the only guaranteed method in the protocol for determining whether a record can be returned by a repository (its corresponding item still exists) is through the GetRecord service request.

2.3 Unique Identifier

A unique identifier is a key for extracting metadata from an item in a repository.  The OAI protocol specifies that each item may disseminate metadata in multiple formats. All of the members of this group of possible metadata formats disseminated from a single item share the same unique identifier.  Each record disseminated by a GetRecord or ListRecords protocol request is identified by the combination of this unique identifier and a metadata prefix, which identifies the metadata format.

The format of unique identifiers corresponds to that of  the URI (Uniform Resource Identifier) syntax. An individual community may develop a URI scheme for coordinated use across its repositories. For an example, see the format for identifiers proposed in Appendix 2.

These unique identifiers play two roles in the protocol:

1. Identifiers are returned by both the ListIdentifiers and ListRecords requests; they can be used as keys to request metadata from items.
2. An identifier, in combination with a metadata prefix, is used in the GetRecord protocol request as a means of requesting a record with a specific metadata format from an item.  This means that the resulting record is identified by the combination of the identifier and the metadata prefix.

Note that the identifier described here is not that of the item.  The nature of the item identifier is outside the scope of the OAI protocol.  

Since many clients of the OAI protocol may want to access the content associated with harvested metadata, it is highly recommended that repositories use an element in metadata records to establish a linkage between the record (and its identifier) and the identifier (URL, URN, DOI, etc.) of the associated item.  The mandatory Dublin Core format provides the identifier element that can be used for this purpose.

2.4 Datestamp

A datestamp is the date of creation, deletion, or latest date of modification of an item, the effect of which is a change in the metadata of a record disseminated from that item. Every record returned by the GetRecord and ListRecords service requests contains its respective datestamp in the header.  Datestamps are used as values of optional arguments -- until or from -- to the ListRecords and ListIdentifiers requests to specify selective harvesting (by date) from the repository.  The value of a datestamp must comply to the specifications for dates in the OAI protocol. 

2.5 Set

A set is an optional construct for grouping items in a repository for the purpose of selective harvesting of records. Each repository may define a hierarchical organization of items; the hierarchy can have several top-level nodes.  Each node in the hierarchy is a Set, which has:

• a setTag -- a non-space separated string of alphanumeric characters;
• a setSpec -- a colon [:] separated list of setTags of each node on the path leading from a root element to the actual node;
• a setName -- a string useful for display purposes.

The following is an example of a possible Set hierarchy in a repository:

• Institutions
  • Oceanside University of Nebraska
• Valley View University of Florida
• Subjects
• Existential Kenesiology
• Quantum Psychology

The following table shows a representation of the above Set hierarchy by means of setNames, setTags and setSpecs :

Each item  in a repository may be organized in one Set, several Sets, or no Sets at all. A client should not assume that harvesting every Set in a repository will retrieve records for every item in the repository. Items may also be organized in interior nodes in the Set hierarchy.  Thus, in the example above, it is conceivable that an individual item is organized in both subject and florida. 

The actual meaning of a Set or of the arrangement of Sets in a repository is not defined in the protocol, nor is there any way to derive this meaning through the protocol.  It is expected that individual communities who use the OAI protocol may formulate well-defined Set configurations with perhaps a controlled vocabulary for Set names, and may even develop mechanisms for exposing these to service providers.  For example, a group of cooperating e-print archives in a specific discipline may agree on Sets that arrange items in their repositories based on a controlled subject classification.  Note that there is no mechanism for "reverse lookup"; that is, determining the Set or Sets that an item -- from which a record was disseminated -- is organized in.  

A repository's Set hierarchy is represented in the protocol via setSpecs. ListSets returns the configuration of Sets in a repository as a list of setSpecs.  Any of these setSpecs  can be used as optional arguments to ListRecords or ListIdentifiers to specify the target Set for selective harvesting from the repository.  In the previous example of a Set hierarchy, the setSpec institution:nebraska can be used in a protocol request to return only those records that are disseminated from items organized in the Set represented by this setSpec.  Three  issues should be noted here:

• As described above an individual item may be organized in more than one Set; meaning that different setSpec arguments may return the same record(s).
• As described above an individual item may not be organized in any Set; meaning that an exhaustive repetition of ListRecords  requests with all possible setSpecs will not return all records in the repository.  The only guaranteed method of returning all records is a ListRecords or ListIdentifiers request with no setSpec argument.
• Using a setSpec as an argument in a protocol request will return:
  • all records from items in the Set specified by the setSpec,
  • all records from items in Sets that are descendent from the Set specified by the setSpec.  
    

  Using the previous example of a Set hierarchy, a setSpec of institution to the ListRecords protocol request will return all records from items organized within the institution Set and within the descendent Sets florida and nebraska.

3.0 Protocol Features

3.1 HTTP embedding of OAI requests

3.1.1 HTTP Request Format

In addition to the BASE-URL, all requests consist of a list of keyword arguments, which take the form key=value pairs. Arguments may appear in any order and multiple arguments should be separated by ampersands [&].  At a minimum, each OAI protocol request has one key=value pair that specifies the OAI protocol request issued by the client:

• key is the string 'verb';
• value is one of the defined OAI protocol requests. 

The number and nature of additional key=value pairs is dependent on the arguments for the individual protocol request.

Libraries such as libwww-perl will decode GET and POST requests seamlessly; the application does not even need to know which method was used. The advantage of POST is that there are no limitations on the length of the arguments.

3.1.1.1 Encoding an OAI protocol request in a URL for an HTTP GET

http://an.oa.org/OAI-script?
  verb=GetRecord&identifier=oai:arXiv:hep-th/9901001&metadataPrefix=oai_dc

However, since special characters in URIs must be encoded, the valid form of the above above GET request URL is:

http://an.oa.org/OAI-script?
  verb=GetRecord&identifier=oai%3AarXiv%3Ahep-th%2F9901001&metadataPrefix=oai_dc

3.1.1.2 Encoding an OAI protocol request in an HTTP POST

POST http://an.oa.org/OAI-script HTTP/1.0
Content-Length: 78
Content-Type: application/x-www-form-urlencoded
verb=GetRecord&identifier=oai%3AarXiv%3Ahep-th%2F9901001&metadataPrefix=oai_dc

3.1.1.3 Encoding of special characters in keyword arguments of OAI protocol requests

• The use of character references is preferred over the use of entity references.  Character references allow XML responses to be treated as stand-alone documents that can be manipulated without dependency on entity declarations external to the document.
• The use of a hexadecimal representation of character references is preferred over decimal representations, since Unicode character encodings are defined using hex numbers. For instance, &#x00A9; is preferred over &#169; for encoding © .

• 302 - Allows the repository to temporarily redirect an OAI protocol request to another repository. The URI of the temporary repository should be given by the Location field in the HTTP response.

• 503 - Service unavailable, a Retry-After period is specified.  Clients should wait this period before attempting another OAI protocol request (Clients that do not observe the Retry-After period may be denied access). 

• Protocol Requests: Values for the optional from and until arguments in ListIdentifiers and ListRecords protocol requests, as well as for datestamps in the headers of records are encoded using the "Complete date" variant of ISO8601. That format is YYYY-MM-DD where YYYY is the year, MM is the month of the year between 01 (January) and 12 (December), and DD is the day of the month between 01 and 28 or 29 or 30 or 31, depending on length of month and whether it is a leap year. For example: 1957-03-20 is March 20th 1957.
• Protocol Responses:  Each protocol response includes a responseDate element, which must be the time and date of the response in the local time of the repository.  This is encoded using the "Complete date plus hours, minutes and seconds" variant of ISO8601.   That format is YYYY-MM-DDThh:mm:ssTZD, with the following meanings:
  • YYYY, MMM, DD is the same as for dates.  
  • T is the character "T", 
  • hh are the hours (between 00 and 23), mm are the minutes (between 00 and 59) and ss the seconds (between 00 and 59). 
  • TZD is an indication of the time zone of the repository, expressed as an offset from UTC.  A time zone offset of "+hh:mm" indicates that the date/time uses a local time zone which is "hh" hours and "mm" minutes ahead of UTC. A time zone offset of "-hh:mm" indicates that the date/time uses a local time zone which is "hh" hours and "mm" minutes behind UTC. 

  For instance, 1957-03-20T20:30:00+00:00 is UTC 8:30 PM on March 20th 1957.

• A repository replies to a protocol request with an incomplete list and a resumptionToken;
• In order to make the response a complete list, the client will need to issue one or more protocol requests with resumptionTokens as arguments.  A complete response then consists of the combination of the incomplete lists from the sequence of protocol requests.

4. Protocol Requests and Responses

Arguments

Exception Conditions

• Identifier does not exist - The response will not contain a record container.
• Metadata format can not be disseminated for the identifier - The record in the response contains a header but no metadata container.

Response Format

<schema xmlns="http://www.w3.org/2001/XMLSchema"

        xmlns:oai="http://www.openarchives.org/OAI/1.1/OAI_GetRecord"

        targetNamespace="http://www.openarchives.org/OAI/1.1/OAI_GetRecord"

        elementFormDefault="qualified"

        attributeFormDefault="unqualified">



<annotation>

 <documentation>

   Schema to verify validity of responses to GetRecord OAI-protocol request.

   This Schema validated at http://www.w3.org/2001/03/webdata/xsv on 2001-05-07

   with XSV XSV 1.189/1.95 of 2001/05/07 08:38:12

 </documentation>

</annotation>



<element name="GetRecord" type="oai:GetRecordType"/>



<!-- response to GetRecord-request -->



<complexType name="GetRecordType">

 <sequence>

   <element name="responseDate" minOccurs="1" maxOccurs="1" type="dateTime"/>

   <element name="requestURL" minOccurs="1" maxOccurs="1" type="anyURI"/>

   <element name="record" minOccurs="0" maxOccurs="1" type="oai:recordType"/>

 </sequence>

</complexType>



<!-- define recordType -->

<!-- a record has a header and a metadata part -->



<complexType name="recordType">

 <sequence>

   <element name="header" minOccurs="1" maxOccurs="1" type="oai:headerType"/>

   <element name="metadata" minOccurs="0" maxOccurs="1" type="oai:metadataType"/>

   <element name="about" minOccurs="0" maxOccurs="1" type="oai:aboutType"/>

 </sequence>

    <attribute name="status" use="optional" type="oai:statusType"/>

</complexType>



<!-- define headerType -->

<!-- a header has a unique identifier and a datestamp -->



<complexType name="headerType">

 <sequence>

   <element name="identifier" minOccurs="1" maxOccurs="1" type="anyURI"/>

   <element name="datestamp" minOccurs="1" maxOccurs="1" type="date"/>

 </sequence>

</complexType>



<!-- define metadataType -->

<!-- metadata must be expressed in XML that is compliant with another XML  -->

<!-- Schema. metadata must be explicitly qualified in the response -->



<complexType name="metadataType">

 <sequence>

  <any namespace="##other" processContents="lax"/>

 </sequence>

</complexType>



<!-- define aboutType -->

<!-- data "about" the record must be expressed in XML -->

<!-- that is compliant with an XML Schema defined by a community -->



<complexType name="aboutType">

 <sequence>

  <any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="1"/>

 </sequence>

</complexType>



 <!-- define statusType -->
 <!-- a record can have a status of "deleted" . -->

<simpleType name="statusType">

  <restriction base="string">

   <enumeration value="deleted"/>

  </restriction>

</simpleType>





</schema>

Request

http://an.oa.org/OAI-script?

       verb=GetRecord&identifier=oai:arXiv:quant-ph/9901001&metadataPrefix=oai_dc

Response

<?xml version="1.0" encoding="UTF-8"?>

 <GetRecord 
    xmlns="http://www.openarchives.org/OAI/1.1/OAI_GetRecord"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/OAI_GetRecord         

                  http://www.openarchives.org/OAI/1.1/OAI_GetRecord.xsd">

  <responseDate>2001-06-10T14:09:57-07:00</responseDate>

  <requestURL>http://an.oa.org/OAI-script?verb=GetRecord
              &amp;identifier=oai%3AarXiv%3Aquant-ph%2F9901001
              &amp;metadataPrefix=oai_dc</requestURL>

  <record>

   <header>

    <identifier>oai:arXiv:quant-ph/9901001</identifier>

    <datestamp>1999-01-01</datestamp>

   </header>

   <metadata>

   <dc xmlns="http://purl.org/dc/elements/1.1/" 

       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

       xsi:schemaLocation="http://purl.org/dc/elements/1.1/

                           http://www.openarchives.org/OAI/1.1/dc.xsd">

     <title>Quantum slow motion</title>

     <creator>Hug, M.</creator>

     <creator>Milburn, G. J.</creator>

     <description>We simulate the center of mass motion of cold atoms in a standing, 
      amplitude modulated, laser field as an example of a system that has a classical 

      mixed phase-space.</description>

     <date>1999-01-01</date>

     <type>e-print</type>

     <identifier>http://arXiv.org/abs/quant-ph/9901001</identifier>

    </dc>

   </metadata>

  </record>

 </GetRecord>

Request

http://an.oa.org/OAI-script?

       verb=GetRecord&identifier=oai:arXiv:quant-ph/0201001&metadataPrefix=oai_dc

Response

<?xml version="1.0" encoding="UTF-8"?>

 <GetRecord 
    xmlns="http://www.openarchives.org/OAI/1.1/OAI_GetRecord"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/OAI_GetRecord         

                  http://www.openarchives.org/OAI/1.1/OAI_GetRecord.xsd">

  <responseDate>2001-06-10T14:09:57-07:00</responseDate>

  <requestURL>http://an.oa.org/OAI-script?verb=GetRecord
              &amp;identifier=oai%3AarXiv%3Aquant-ph%2F0201001
              &amp;metadataPrefix=oai_dc</requestURL>

 </GetRecord>

Request

http://an.oa.org/OAI-script?

       verb=GetRecord&identifier=oai:arXiv:quant-ph/9901001&metadataPrefix=oai_marc

Response

<?xml version="1.0" encoding="UTF-8"?>

 <GetRecord 
    xmlns="http://www.openarchives.org/OAI/1.1/OAI_GetRecord"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/OAI_GetRecord         

                  http://www.openarchives.org/OAI/1.1/OAI_GetRecord.xsd">

  <responseDate>2001-06-10T14:09:57-07:00</responseDate>

  <requestURL>http://an.oa.org/OAI-script?verb=GetRecord
              &amp;identifier=oai%3AarXiv%3Aquant-ph%2F9901001
              &amp;metadataPrefix=oai_marc</requestURL>

  <record>

   <header>

    <identifier>oai:arXiv:quant-ph/9901001</identifier>

    <datestamp>1999-01-01</datestamp>

   </header>

  </record>

 </GetRecord>

4.2. Identify

Arguments

None

Exception Conditions

None

Response Format

<schema xmlns="http://www.w3.org/2001/XMLSchema"

        xmlns:oai="http://www.openarchives.org/OAI/1.1/OAI_Identify"

        targetNamespace="http://www.openarchives.org/OAI/1.1/OAI_Identify"

        elementFormDefault="qualified"

        attributeFormDefault="unqualified">



<annotation>

 <documentation>

   Schema to verify validity of responses to Identify OAI-protocol request.

   This Schema validated at http://www.w3.org/2001/03/webdata/xsv on 2001-05-07

   with XSV XSV 1.189/1.95 of 2001/05/07 08:38:12

 </documentation>

</annotation>



<element name="Identify" type="oai:IdentifyType"/>



<!-- response to Identify-request -->



<complexType name="IdentifyType">

 <sequence>

   <element name="responseDate" minOccurs="1" maxOccurs="1" type="dateTime"/>

   <element name="requestURL" minOccurs="1" maxOccurs="1" type="anyURI"/>

   <element name="repositoryName" minOccurs="1" maxOccurs="1" type="string"/>

   <element name="baseURL" minOccurs="1" maxOccurs="1" type="anyURI"/>

   <element name="protocolVersion" minOccurs="1" maxOccurs="1" type="string"/>

   <element name="adminEmail" minOccurs="1" maxOccurs="1" type="anyURI"/>

   <element name="description" minOccurs="0" maxOccurs="unbounded" 
            type="oai:descriptionType"/>

 </sequence>

</complexType>



<complexType name="descriptionType">

 <sequence>

  <any namespace="##other" processContents="lax"/>

 </sequence>

</complexType>



</schema>

Examples

Request

http://an.oa.org/OAI-script?

       verb=Identify

Response

The response to this protocol request includes the following elements that must be provided by every OAI compliant repository:

• repositoryName: a human readable name for the repository, in the example "The University of Spa E-print System";
• baseURL: the BASE-URL of the repository;
• protocolVersion: the version of the OAI protocol supported by the repository;
• adminEmail: the e-mail address of the administrator of the repository.

In addition, the response may contain a list of description containers, which provide an extensible mechanism for communities to describe their repositories.  The description container, could -- for instance -- be used to include collection-level metadata in the response to the Identify request. Each description container must be accompanied by the URL of an XML schema, which provides the semantics of the descriptive container.  The below example of a response to the Identify request contains two description containers:

• The oai-identifier container complies to an XML Schema, which is available at http://www.openarchives.org/OAI/1.1/oai-identifier.xsd. This schema, shown in Appendix 2, is used by repositories that choose to comply with a specific format of unique identifiers for records. The format of that identifier is explained by means of comments in the oai-identifier.xsd XML Schema.
• The eprints container complies to an XML Schema, which is available at http://www.openarchives.org/OAI/1.1/eprints.xsd. This schema, shown in Appendix 2, has been agreed upon by the OAI e-print community, and contains information specific to repositories in that community.

<?xml version="1.0" encoding="UTF-8"?>

  <Identify 
     xmlns="http://www.openarchives.org/OAI/1.1/OAI_Identify"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

     xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/OAI_Identify         

                   http://www.openarchives.org/OAI/1.1/OAI_Identify.xsd">

    <responseDate>2001-06-01T19:20:30-04:00</responseDate>

    <requestURL>http://an.oa.org/OAI-script?verb=Identify</requestURL>

    <repositoryName>The University of Spa E-print System</repositoryName>

    <baseURL>http://an.oa.org/OAI-script</baseURL>

    <protocolVersion>1.1</protocolVersion>

    <adminEmail>mailto:adm&#x0040;spa.ac.be</adminEmail>

    <description>

      <oai-identifier xmlns="http://www.openarchives.org/OAI/1.1/oai-identifier"
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

            xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/oai-identifier         

                          http://www.openarchives.org/OAI/1.1/oai-identifier.xsd">

        <scheme>oai</scheme>

        <repositoryIdentifier>bespa</repositoryIdentifier>

        <delimiter>:</delimiter>

        <sampleIdentifier>oai:bespa:medi99-123</sampleIdentifier>

      </oai-identifier>

    </description>

    <description>

      <eprints xmlns="http://www.openarchives.org/OAI/1.1/eprints"
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

            xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/eprints         

                                http://www.openarchives.org/OAI/1.1/eprints.xsd">

        <content>

          <URL>http://an.oa.org/info/content.htm</URL>

        </content>

        <metadataPolicy>

          <text>Metadata can be used by commercial and non-commercial service
           providers</text>

          <URL>http://an.oa.org/info/metadata_use.htm</URL>

        </metadataPolicy>

        <dataPolicy>

          <text>Full content, i.e. preprints may not be harvested by robots</text>

        </dataPolicy>

        <submissionPolicy>

          <URL>http://an.oa.org/info/submission.htm</URL>

        </submissionPolicy>

      </eprints>

    </description>

  </Identify> 

Arguments

Exception Conditions

• No records match the request - The response will not contain any identifier elements.

Response Format

<schema xmlns="http://www.w3.org/2001/XMLSchema"

        xmlns:oai="http://www.openarchives.org/OAI/1.1/OAI_ListIdentifiers"

        targetNamespace="http://www.openarchives.org/OAI/1.1/OAI_ListIdentifiers"

        elementFormDefault="qualified"

        attributeFormDefault="unqualified">



<annotation>

 <documentation>

   Schema to verify validity of responses to ListIdentifiers OAI-protocol request.

   This Schema validated at http://www.w3.org/2001/03/webdata/xsv on 2001-05-07

   with XSV XSV 1.189/1.95 of 2001/05/07 08:38:12

 </documentation>

</annotation>



<element name="ListIdentifiers" type="oai:ListIdentifiersType"/>



<!-- response to ListIdentifiers-request -->

<!-- records have an optional "deleted" status -->

<!-- this response may contain an optional resumptionToken -->



<complexType name="ListIdentifiersType">

 <sequence>

   <element name="responseDate" minOccurs="1" maxOccurs="1" type="dateTime"/>

   <element name="requestURL" minOccurs="1" maxOccurs="1" type="anyURI"/>

   <element ref="oai:identifier" minOccurs="0" maxOccurs="unbounded"/>

   <element name="resumptionToken" minOccurs="0" maxOccurs="1" type="string"/>

 </sequence>

</complexType>



<element name="identifier">

 <complexType>

  <simpleContent>

   <extension base="anyURI">

    <attribute name="status" use="optional" type="oai:statusType"/>

   </extension>

  </simpleContent>

 </complexType>

</element>



 <!-- define statusType -->
 <!-- a record can have a status of "deleted" . -->

<simpleType name="statusType">

  <restriction base="string">

   <enumeration value="deleted"/>

  </restriction>

</simpleType>

</schema>

Examples

Request

http://an.oa.org/OAI-script?



       verb=ListIdentifiers&from=1998-01-15&set=physics:hep

Response

<?xml version="1.0" encoding="UTF-8"?>

  <ListIdentifiers 
      xmlns="http://www.openarchives.org/OAI/1.1/OAI_ListIdentifiers"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

      xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/OAI_ListIdentifiers         

                    http://www.openarchives.org/OAI/1.1/OAI_ListIdentifiers.xsd">

    <responseDate>2001-06-01T19:20:30-04:00</responseDate>

    <requestURL>http://an.oa.org/OAI-script?verb=ListIdentifiers
                &amp;from=1998-01-15&amp;setSpec=physics%3Ahep</requestURL>

     <identifier>oai:arXiv:hep-th/9801001</identifier>

     <identifier>oai:arXiv:hep-th/9801002</identifier>

     <identifier>oai:arXiv:hep-th/9801005</identifier>

     <identifier status="deleted">oai:arXiv:hep-th/9801010</identifier>

    <resumptionToken>xxx45abttyz</resumptionToken>

  </ListIdentifiers>

Request

http://an.oa.org/OAI-script?

       verb=ListIdentifiers&resumptionToken=xxx45abttyz

Response

<?xml version="1.0" encoding="UTF-8"?>

  <ListIdentifiers 
      xmlns="http://www.openarchives.org/OAI/1.1/OAI_ListIdentifiers"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

      xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/OAI_ListIdentifiers         

                    http://www.openarchives.org/OAI/1.1/OAI_ListIdentifiers.xsd">

    <responseDate>2001-06-01T19:20:30-04:00</responseDate>

    <requestURL>http://an.oa.org/OAI- script?verb=ListIdentifiers

                &amp;resumptionToken=xxx45abttyz</requestURL>

     <identifier>oai:arXiv:hep-th/9801020</identifier>

     <identifier>oai:arXiv:hep-th/9801060</identifier>

  </ListIdentifiers>

Request

http://an.oa.org/OAI-script?



       verb=ListIdentifiers&from=2001-01-01&until=2001-01-01&set=physics:hep

Response

<?xml version="1.0" encoding="UTF-8"?>

  <ListIdentifiers 
      xmlns="http://www.openarchives.org/OAI/1.1/OAI_ListIdentifiers"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

      xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/OAI_ListIdentifiers         

                    http://www.openarchives.org/OAI/1.1/OAI_ListIdentifiers.xsd">

    <responseDate>2001-06-01T19:20:30-04:00</responseDate>

    <requestURL>http://an.oa.org/OAI-script?verb=ListIdentifiers
                &amp;from=2001-01-01&amp;until=2001-01-01
                &amp;setSpec=physics%3Ahep</requestURL>

  </ListIdentifiers>

Arguments

Exception Conditions

• The identifier does not exist - The response will not contain a metadataFormat container.

Response Format

<schema xmlns="http://www.w3.org/2001/XMLSchema"

  xmlns:oai="http://www.openarchives.org/OAI/1.1/OAI_ListMetadataFormats"

  targetNamespace="http://www.openarchives.org/OAI/1.1/OAI_ListMetadataFormats"

  elementFormDefault="qualified"

  attributeFormDefault="unqualified">



<annotation>

 <documentation>

   Schema to verify validity of responses to ListMetadataFormats OAI-protocol 

   request.

   This Schema validated at http://www.w3.org/2001/03/webdata/xsv on 2001-05-07

   with XSV XSV 1.189/1.95 of 2001/05/07 08:38:12

 </documentation>

</annotation>



<element name="ListMetadataFormats" type="oai:ListMetadataType"/>



<!-- response to ListMetadataFormats-request -->



<complexType name="ListMetadataType">

 <sequence>

    <element name="responseDate" minOccurs="1" maxOccurs="1" type="dateTime"/>

    <element name="requestURL" minOccurs="1" maxOccurs="1" type="anyURI"/>

    <element name="metadataFormat" minOccurs="0" maxOccurs="unbounded" 
             type="oai:metadataFormatType"/>

 </sequence>

</complexType>



<complexType name="metadataFormatType">

 <sequence>

   <element name="metadataPrefix" minOccurs="1" maxOccurs="1" 
            type="oai:metadataPrefixType"/>

   <element name="schema" minOccurs="1" maxOccurs="1" type="anyURI"/>

   <element name="metadataNamespace" minOccurs="0" maxOccurs="1" 
            type="anyURI"/>

 </sequence>

</complexType>



<simpleType name="metadataPrefixType">

 <restriction base="string">

   <pattern value="[a-zA-Z0-9_]+"/>

 </restriction>

</simpleType>



</schema>

Examples

Request

List the metadata formats that can be disseminated from the record with unique identifier oai:arXiv:hep-th/9901001 [URL shown without encoding for better readability].

http://an.oa.org/OAI-script?

       verb=ListMetadataFormats&identifier=oai:arXiv:hep-th/9901001

Response

<?xml version="1.0" encoding="UTF-8"?>

  <ListMetadataFormats 
      xmlns="http://www.openarchives.org/OAI/1.1/OAI_ListMetadataFormats"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

      xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/OAI_ListMetadataFormats         

                    http://www.openarchives.org/OAI/1.1/OAI_ListMetadataFormats.xsd">

    <responseDate>2001-06-01T19:20:30-04:00</responseDate> 

    <requestURL>http://an.oa.org/OAI-script?verb=ListMetadataFormats

                &amp;identifier=oai%3AarXiv%3Ahep-th%2F9901001</requestURL>

    <metadataFormat>

      <metadataPrefix>oai_rfc1807</metadataPrefix>

      <schema>http://www.openarchives.org/OAI/1.1/rfc1807.xsd</schema>

    </metadataFormat>

    <metadataFormat>

      <metadataPrefix>oai_dc</metadataPrefix>

      <schema>http://www.openarchives.org/OAI/1.1/dc.xsd</schema>

      <metadataNamespace>http://purl.org/dc/elements/1.1/</metadataNamespace>

    </metadataFormat>

</ListMetadataFormats> 

Request

List the metadata formats that can be disseminated from the repository http://an.oa.org/OAI-script.

http://an.oa.org/OAI-script?

       verb=ListMetadataFormats

Response

<?xml version="1.0" encoding="UTF-8"?>

  <ListMetadataFormats 
      xmlns="http://www.openarchives.org/OAI/1.1/OAI_ListMetadataFormats"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

      xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/OAI_ListMetadataFormats         

                    http://www.openarchives.org/OAI/1.1/OAI_ListMetadataFormats.xsd">

    <responseDate>2001-06-01T19:20:30-04:00</responseDate> 

    <requestURL>http://an.oa.org/OAI-script?verb=ListMetadataFormats</requestURL>

    <metadataFormat>

      <metadataPrefix>oai_rfc1807</metadataPrefix>

      <schema>http://www.openarchives.org/OAI/1.1/rfc1807.xsd</schema>

    </metadataFormat>

    <metadataFormat>

      <metadataPrefix>oai_dc</metadataPrefix>

      <schema>http://www.openarchives.org/OAI/1.1/dc.xsd</schema>

      <metadataNamespace>http://purl.org/dc/elements/1.1/</metadataNamespace>

    </metadataFormat>

    <metadataFormat>

      <metadataPrefix>oai_marc</metadataPrefix>

      <schema>http://www.openarchives.org/OAI/1.1/oai_marc.xsd</schema>

    </metadataFormat>

</ListMetadataFormats> 

Request

List the metadata formats that can be disseminated from the record with unique identifier oai:arXiv:hep-th/0101001. The identifier, however, does not exist and therefore, the response does not contain a metadataFormat container. [URL shown without encoding for better readability].

http://an.oa.org/OAI-script?

       verb=ListMetadataFormats&identifier=oai:arXiv:hep-th/0101001

Response

<?xml version="1.0" encoding="UTF-8"?>

  <ListMetadataFormats 
      xmlns="http://www.openarchives.org/OAI/1.1/OAI_ListMetadataFormats"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

      xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/OAI_ListMetadataFormats         

                    http://www.openarchives.org/OAI/1.1/OAI_ListMetadataFormats.xsd">

    <responseDate>2001-06-01T19:20:30-04:00</responseDate> 

    <requestURL>http://an.oa.org/OAI-script?verb=ListMetadataFormats

                &amp;identifier=oai%3AarXiv%3Ahep-th%2F0101001</requestURL>

</ListMetadataFormats> 

Arguments

Exception Conditions

• No records match the request - The response will not contain any record containers.
• Requested metadata format can not be disseminated for a matching record - The response record contains a header but no metadata container.

Response Format

<schema xmlns="http://www.w3.org/2001/XMLSchema"

         xmlns:oai="http://www.openarchives.org/OAI/1.1/OAI_ListRecords"

         targetNamespace="http://www.openarchives.org/OAI/1.1/OAI_ListRecords"

         elementFormDefault="qualified"

         attributeFormDefault="unqualified">



 <annotation>

  <documentation>

    Schema to verify validity of responses to ListRecords OAI-protocol request.

    This Schema validated at http://www.w3.org/2001/03/webdata/xsv on 2001-05-07

    with XSV XSV 1.189/1.95 of 2001/05/07 08:38:12

  </documentation>

 </annotation>



 <element name="ListRecords" type="oai:ListRecordsType"/>



 <!-- response to ListRecords-request -->

 <!-- this response may contain an optional resumptionToken -->



 <complexType name="ListRecordsType">

  <sequence>

    <element name="responseDate" minOccurs="1" maxOccurs="1" type="dateTime"/>

    <element name="requestURL" minOccurs="1" maxOccurs="1" type="anyURI"/>

    <element name="record" minOccurs="0" maxOccurs="unbounded" 
             type="oai:recordType"/>

    <element name="resumptionToken" minOccurs="0" maxOccurs="1" type="string"/>

  </sequence>

  </complexType>



 <!-- define recordType -->

 <!-- a record has a header and a metadata part -->



 <complexType name="recordType">

  <sequence>

    <element name="header" minOccurs="1" maxOccurs="1" type="oai:headerType"/>

    <element name="metadata" minOccurs="0" maxOccurs="1" type="oai:metadataType"/>

    <element name="about" minOccurs="0" maxOccurs="1" type="oai:aboutType"/>

  </sequence>

  <attribute name="status" use="optional" type="oai:statusType"/>

 </complexType>



 <!-- define headerType -->

 <!-- a header has a unique identifier and a datestamp -->



 <complexType name="headerType">

  <sequence>

    <element name="identifier" minOccurs="1" maxOccurs="1" type="anyURI"/>

    <element name="datestamp" minOccurs="1" maxOccurs="1" type="date"/>

  </sequence>

 </complexType>



 <!-- define metadataType -->

 <!-- metadata must be expressed in XML that complies with another XML Schema -->

 <!-- metadata must be explicitly qualified in the response -->



 <complexType name="metadataType">

  <sequence>

   <any namespace="##other" processContents="lax"/>

  </sequence>

 </complexType>



<!-- define aboutType -->

<!-- data "about" the record must be expressed in XML -->

<!-- that is compliant with an XML Schema defined by a community -->



<complexType name="aboutType">

 <sequence>

  <any namespace="##other" processContents="lax" minOccurs="0" maxOccurs="1"/>

 </sequence>

</complexType>



 <!-- define statusType -->
 <!-- a record can have a status of "deleted" . -->

<simpleType name="statusType">

  <restriction base="string">

   <enumeration value="deleted"/>

  </restriction>

</simpleType>

</schema>

Examples

Request

http://an.oa.org/OAI-script?

       verb=ListRecords&from=1998-01-15&set=physics:hep&metadataPrefix=oai_rfc1807

Response

<?xml version="1.0" encoding="UTF-8"?>

  <ListRecords 
      xmlns="http://www.openarchives.org/OAI/1.1/OAI_ListRecords"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

      xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/OAI_ListRecords         

                    http://www.openarchives.org/OAI/1.1/OAI_ListRecords.xsd">

    <responseDate>2001-06-01T19:20:30-04:00</responseDate> 

    <requestURL>http://an.oa.org/OAI-script?verb=ListRecords
                &amp;from=1998-01-15&amp;setSpec=physics%3Ahep
                &amp;metadataPrefix=oai_rfc1807</requestURL>

    <record>

      <header>

        <identifier>oai:arXiv:hep-th/9901001</identifier>

        <datestamp>1999-12-25</datestamp>

      </header>

      <metadata>

       <rfc1807 
         xmlns="http://info.internet.isi.edu:80/in-notes/rfc/files/rfc1807.txt" 

         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

         xsi:schemaLocation=
             "http://info.internet.isi.edu:80/in-notes/rfc/files/rfc1807.txt

              http://www.openarchives.org/OAI/1.1/rfc1807.xsd">
          <bib-version>v2</bib-version>
          <id>hep-th/9901001</id>

          <entry>January 1, 1999</entry>
          <title>Investigations of Radioactivity</title>

          <author>Ernest Rutherford</author>

          <date>March 30, 1999</date>

        </rfc1807>

      </metadata>

      <about>

       <dc xmlns="http://purl.org/dc/elements/1.1/" 

         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

         xsi:schemaLocation="http://purl.org/dc/elements/1.1/

                             http://www.openarchives.org/OAI/1.1/dc.xsd">

        <publisher>Los Alamos arXiv</publisher>

        <rights>Metadata may be used without restrictions as long as the oai 
         identifier remains attached to it.</rights>

       </dc>

      </about>

    </record>

    <record>

      <header>

        <identifier>oai:arXiv:hep-th/9901004</identifier>

        <datestamp>1999-12-26</datestamp>

      </header>

    </record>

    <record status="deleted">

      <header>

        <identifier>oai:arXiv:hep-th/9901007</identifier>

        <datestamp>1999-12-21</datestamp>

      </header>

    </record>

  </ListRecords>

Arguments

• resumptionToken an EXCLUSIVE argument with a value that is the flow control token returned by a previous ListSets request that issued a partial response.

Exception Conditions

• Repository contains no set hierarchy - The response will not contain any set containers.

Response Format

<schema xmlns="http://www.w3.org/2001/XMLSchema"

         xmlns:oai="http://www.openarchives.org/OAI/1.1/OAI_ListSets"

         targetNamespace="http://www.openarchives.org/OAI/1.1/OAI_ListSets"

         elementFormDefault="qualified"

         attributeFormDefault="unqualified">



  <annotation>

   <documentation>

    Schema to verify validity of responses to ListSets OAI-protocol request.

    This Schema validated at http://www.w3.org/2001/03/webdata/xsv on 2001-05-07

    with XSV XSV 1.189/1.95 of 2001/05/07 08:38:12

   </documentation>

  </annotation>



 <element name="ListSets" type="oai:ListSetsType"/>



 <!-- this response may contain an optional resumptionToken -->



 <complexType name="ListSetsType">

  <sequence>

    <element name="responseDate" minOccurs="1" maxOccurs="1" type="dateTime"/>

    <element name="requestURL" minOccurs="1" maxOccurs="1" type="anyURI"/>

    <element name="set" minOccurs="0" maxOccurs="unbounded" type="oai:setType"/>

    <element name="resumptionToken" minOccurs="0" maxOccurs="1" type="string"/>

  </sequence>

 </complexType>



 <!-- each set in the list consists of a setSpec and a pretty name -->



 <complexType name="setType">

  <sequence>

    <element name="setSpec" minOccurs="1" maxOccurs="1" type="oai:setSpecType"/>

    <element name="setName" minOccurs="1" maxOccurs="1" type="string"/>

  </sequence>

 </complexType>



 <simpleType name="setSpecType">

    <restriction base="string">

    <pattern value="([A-Za-z0-9])+(:[A-Za-z0-9]+)*"/>

    </restriction>

 </simpleType>



 </schema>

Examples

Request

http://an.oa.org/OAI-script?

       verb=ListSets

Response

The following response indicates a set hierarchy with two top level sets - Oceanside and ValleyView - each with two sets within them.

<?xml version="1.0" encoding="UTF-8"?>

  <ListSets 
      xmlns="http://www.openarchives.org/OAI/1.1/OAI_ListSets"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

      xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/OAI_ListSets         

                    http://www.openarchives.org/OAI/1.1/OAI_ListSets.xsd">

    <responseDate>2001-06-01T19:20:30-04:00</responseDate> 

    <requestURL>http://an.oa.org/OAI-script?verb=ListSets</requestURL>

    <set>

      <setSpec>Oceanside</setSpec>

      <setName>Oceanside University of Nebraska</setName>

    </set>

    <set>

      <setSpec>Oceanside:CompEnt</setSpec>

      <setName>Department of Computational Entomology</setName>

    </set>

    <set>

      <setSpec>Oceanside:MetPhen</setSpec>

      <setName>Department of Metaphysical Phenomenology</setName>

    </set>

    <set>

      <setSpec>ValleyView</setSpec>

      <setName>Valley View University of Florida</setName>

    </set>

    <set>

      <setSpec>ValleyView:Fren</setSpec>

      <setName>Department of Frenetics</setName>

    </set>

    <set>

      <setSpec>ValleyView:Hist</setSpec>

      <setName>Department of Histrionics</setName>

    </set>

</ListSets>

http://another.oa.org/OAI-script?

       verb=ListSets

<?xml version="1.0" encoding="UTF-8"?>

  <ListSets 
      xmlns="http://www.openarchives.org/OAI/1.1/OAI_ListSets"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

      xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/OAI_ListSets         

                    http://www.openarchives.org/OAI/1.1/OAI_ListSets.xsd">

    <responseDate>2001-06-01T19:20:30-04:00</responseDate> 

    <requestURL>http://another.oa.org/OAI-script?verb=ListSets</requestURL>

  </ListSets>

Appendix 1: Sample XML schema for metadata formats

Each metadata format that is included in records disseminated by the OAI protocol is identified within the repository by a metadata prefix and across multiple repositories by the URL of a metadata schema. The metadata schema is an XML schema that may be used as a test of conformance of the metadata included in the record. XML Schemas for three metadata formats are given below:

• An XML Schema for the mandatory unqualified Dublin Core metadata format;
• An XML Schema for the rfc1807 metadata format;
• An XML Schema to represent MARC21 records in an XML format.

<schema xmlns="http://www.w3.org/2001/XMLSchema"

         xmlns:dc="http://purl.org/dc/elements/1.1/"

         targetNamespace="http://purl.org/dc/elements/1.1/"

         elementFormDefault="qualified"

         attributeFormDefault="unqualified">



  <annotation>

   <documentation>

    Schema for Dublin Core metadata format.

    the Open Archives Initiative. 2000. 

    Schema validated at http://www.w3.org/2001/03/webdata/xsv on 05-09-2001

    Dublin Core semantics available at 
           http://purl.org/DC/documents/rec-dces-19990702.htm

   </documentation>

  </annotation>



<element name="dc" type="dc:dublincoreType"/>



<complexType name="dublincoreType">

 <choice minOccurs="0" maxOccurs="unbounded">

  <element name="title" minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="creator"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="subject"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="description"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="contributor"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="publisher"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="date"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="type"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="format"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="identifier"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="source"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="language"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="relation"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="coverage"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="rights"  minOccurs="0" maxOccurs="unbounded" type="string"/>

 </choice>

</complexType>



 </schema>

Examples

<dc xmlns="http://purl.org/dc/elements/1.1/" 

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

    xsi:schemaLocation="http://purl.org/dc/elements/1.1/

                        http://www.openarchives.org/OAI/1.1/dc.xsd">

<title>The Cornell Law Quarterly</title>

<date>1915-1916</date>

<identifier>http://heinonline.org/HeinOnline/show.pl?
            handle=hein.journals/clqv1%26id=1%26size=4</identifier>

<rights>Available by Subscription. See http://www.wshein.com</rights>

</dc>



<dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" 

       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

       xsi:schemaLocation="http://purl.org/dc/elements/1.1/

                           http://www.openarchives.org/OAI/1.1/dc.xsd">

<dc:title>Grassmann's space analysis</dc:title> 

<dc:creator>Hyde, E. W. (Edward Wyllys)</dc:creator>

<dc:subject>LCSH:Ausdehnungslehre; LCCN QA205.H99</dc:subject>

<dc:publisher>J. Wiley &amp; Sons</dc:publisher>

<dc:date>Created: 1906; Available: 1991</dc:date>

<dc:type>text</dc:type>

<dc:identifier>http://resolver.library.cornell.edu/math/1796949</dc:identifier>

<dc:language>eng</dc:language>

<dc:rights>Public Domain</dc:rights>

</dc:dc>

<schema xmlns="http://www.w3.org/2001/XMLSchema"

   xmlns:rfc1807="http://info.internet.isi.edu:80/in-notes/rfc/files/rfc1807.txt"

   targetNamespace="http://info.internet.isi.edu:80/in-notes/rfc/files/rfc1807.txt"

   elementFormDefault="qualified"

   attributeFormDefault="unqualified">



  <annotation>

   <documentation>

    Schema for rfc1807 metadata format.

    the Open Archives Initiative. 2000. 

    rfc1807 semantics available at 
            http://info.internet.isi.edu:80/in-notes/rfc/files/rfc1807.txt

    XML transportation format on which this schema is inspired 

        available at http://www.openarchives.org/sfc/sfc_rfc1807.htm

    This Schema was validated with XSV 1.196/1.98 of 2001/06/16 11:56:53

   </documentation>

  </annotation>



<element name="rfc1807" type="rfc1807:rfc1807Type"/>



<complexType name="rfc1807Type">

 <sequence>

  <element name="bib-version" minOccurs="1" maxOccurs="1" type="string"/>

  <element name="id"  minOccurs="1" maxOccurs="1" type="string"/>

  <element name="entry"  minOccurs="1" maxOccurs="1" type="string"/>

  <element name="organization"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="title"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="type"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="revision"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="withdraw"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="author"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="corp-author"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="contact"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="date"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="pages"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="copyright"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="handle"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="other_access"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="retrieval"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="keyword"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="cr-category"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="period"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="series"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="monitoring"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="funding"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="contract"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="grant"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="language"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="notes"  minOccurs="0" maxOccurs="unbounded" type="string"/>

  <element name="abstract"  minOccurs="0" maxOccurs="unbounded" type="string"/>

 </sequence>

</complexType>



 </schema>

<schema xmlns="http://www.w3.org/2001/XMLSchema"
   targetNamespace="http://www.openarchives.org/OAI/1.1/oai_marc"
   xmlns:oai_marc="http://www.openarchives.org/OAI/1.1/oai_marc"
   elementFormDefault="qualified"
   attributeFormDefault="unqualified">

   <annotation>
     <documentation>
      Schema for MARC metadata format.
      MARC semantics available at http://www.loc.gov/marc/
      .....
      This Schema has been successfully applied for MARC21 records.  
      It is likely to also work for older versions of USMARC and CANMARC.  
      Application of this Schema for other MARC formats has not been 
      tested and may require some adjustments. 
      ..... 
      the Open Archives Initiative. 2000. 
      Herbert Van de Sompel
      MARC XML transportation format on which this schema is inspired 
           available at http://www.dlib.vt.edu/projects/OAi/marcxml/marcxml.html
     This Schema validated at http://www.w3.org/2001/03/webdata/xsv on 05-09-2001.
     </documentation>
    </annotation>

  <element name="oai_marc">
   <complexType>
     <sequence>
       <element ref="oai_marc:fixfield" minOccurs="1" maxOccurs="unbounded"/>
       <element ref="oai_marc:varfield" minOccurs="0" maxOccurs="unbounded"/>
     </sequence>
    <attribute name="status" type="string" use="optional"/>
    <attribute name="type" type="string" use="required"/>
    <attribute name="level" type="string" use="required"/>
    <attribute name="ctlType" type="string" use="optional"/>
    <attribute name="charEnc" type="string" use="optional"/>
    <attribute name="encLvl" type="string" use="optional"/>
    <attribute name="catForm" type="string" use="optional"/>
    <attribute name="lrRqrd" type="string" use="optional"/>
   </complexType>
  </element>

  <element name="fixfield">
   <complexType>
     <simpleContent>
        <extension base="oai_marc:fixfieldType">
        <attribute name="id" type="oai_marc:idType" use="required"/>
        </extension>
     </simpleContent>
   </complexType>
  </element>

  <simpleType name="fixfieldType">
    <restriction base="string">
    <!-- fixfield must be enclosed between quotes because spaces 
         are meaningfull -->
     <pattern value='[\n\r\t\s]*"[^"]*"[\n\r\t\s]*'/>
    </restriction>
  </simpleType>

  <element name="varfield">
   <complexType>
     <sequence>
       <element ref="oai_marc:subfield" minOccurs="1" maxOccurs="unbounded"/>
     </sequence>
    <attribute name="id" type="oai_marc:idType" use="required"/>
    <attribute name="i1" type="oai_marc:iType" use="required"/>
    <attribute name="i2" type="oai_marc:iType" use="required"/>
   </complexType>
  </element>

  <element name="subfield">
   <complexType>
     <simpleContent>
        <extension base="string">
        <attribute name="label" type="oai_marc:subfieldType" use="required"/>
        </extension>
     </simpleContent>
   </complexType>
  </element>

  <simpleType name="subfieldType">
    <restriction base="string">
    <!-- MARC subfield (the leading $ i not used)
         may be any lowercase alphabetic or numeric character  -->
     <pattern value="[0-9a-z]"/>
    </restriction>
  </simpleType>

  <simpleType name="idType">
    <restriction base="string">
    <!-- MARC tags are 1 to 3 digits -->
     <pattern value="[0-9]{1,3}"/>
    </restriction>
  </simpleType>

  <simpleType name="iType">
    <restriction base="string">
    <!-- MARC indicator may be any lowercase alphabetic or numeric character
         or a blank  -->
     <pattern value="[0-9a-z\s]?"/>
    </restriction>
  </simpleType>


 </schema>

Examples

<oai_marc
    status="n" type="a" level="m" encLvl="7" 
    catForm="a" xmlns="http://www.openarchives.org/OAI/1.1/oai_marc"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

    xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/oai_marc 

                    http://www.openarchives.org/OAI/1.1/oai_marc.xsd">

<fixfield id="1">"   90178038 "</fixfield>

<fixfield id="3">"DLC"</fixfield>

<fixfield id="5">"19900814092959.1"</fixfield>

<fixfield id="8">"900724s1974    po af         000 0 fre  "</fixfield>

<varfield id="10" i1=" " i2=" ">

 <subfield label="a">90178038</subfield>

</varfield>

<varfield id="40" i1=" " i2=" ">

 <subfield label="a">DLC</subfield>

 <subfield label="c">DLC</subfield>

</varfield>

<varfield id="50" i1="0" i2="0">

 <subfield label="a">MLCL 90/00723 (Q)</subfield>

</varfield>

 <varfield id="100" i1="1" i2="0">

 <subfield label="a">Berthou, P. Y.</subfield>

 <subfield label="q">(Pierre Yves)</subfield>

</varfield>

 <varfield id="245" i1="1" i2="3">

 <subfield label="a">Le C&#x00E9;nomanien de l"Estr&#x00E9;madure 
                     portugaise /</subfield>

 <subfield label="c">par Pierre-Yves Berthou.</subfield>

</varfield>

<varfield id="260" i1="0" i2=" ">

 <subfield label="a">Lisboa :</subfield>

 <subfield label="b">Minist&#x00E9;rio da Economia, Secretaria de Estado
           da Ind&#x00FA;stria, Direc&#x00E7;&#x00E3;o-Geral de Minas e 
           Servi&#x00E7;os Geol&#x00F3;gicos, Servi&#x00E7;os 
           Geol&#x00F3;gicos de Portugal,</subfield>

 <subfield label="c">1973 [i.e. 1974]</subfield>

</varfield>

<varfield id="300" i1=" " i2=" ">

 <subfield label="a">168 p., 67 leaves of plates :</subfield>

 <subfield label="b">ill. ;</subfield>

 <subfield label="c">33 cm.</subfield>

</varfield>

<varfield id="490" i1="1" i2=" ">

 <subfield label="a">Mem&#x00F3;ria ;</subfield>

 <subfield label="v">no. 23 (Nova s&#x00E9;r.)</subfield>

</varfield>

<varfield id="653" i1="0" i2=" ">

 <subfield label="a">Stratigraphic geology;</subfield>

 <subfield label="a">Cenomanian deposits;</subfield>

 <subfield label="a">Portugal</subfield>

</varfield>

<varfield id="830" i1=" " i2="0">

 <subfield label="a">Mem&#x00F3;ria (Servi&#x00E7;os Geol&#x00F3;gicos 
           de Portugal) ;</subfield>

 <subfield label="v">nova s&#x00E9;r. no. 23.</subfield>

</varfield>

</oai_marc>

<?xml version="1.0" encoding="UTF-8"?>

  <GetRecord 
     xmlns="http://www.openarchives.org/OAI/1.1/OAI_GetRecord" 

     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 

     xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/OAI_GetRecord 

                   http://www.openarchives.org/OAI/1.1/OAI_GetRecord.xsd">

  <responseDate>2001-01-20T20:32:09-05:00</responseDate>

  <requestURL>http://memory.loc.gov/cgi-bin/oai1_0?verb=GetRecord
      &amp;metadataPrefix=oai_marc
      &amp;identifier=oai%3Alcoa1%3Aloc.gmd%2Fg3711p.rr004620</requestURL>

    <record>

      <header>

        <identifier>oai:lcoa1:loc.gmd/g3711p.rr004620</identifier>

        <datestamp>2000-01-04</datestamp>

      </header>

      <metadata>

      <oai_marc status="c" type="e" level="m" encLvl="1" catForm=" "

                xmlns="http://www.openarchives.org/OAI/oai_marc"

                xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

                xsi:schemaLocation="http://www.openarchives.org/OAI/oai_marc

                                    http://www.openarchives.org/OAI/1.1/oai_marc.xsd">

        <fixfield id="001">"   98688713 "</fixfield>

      <fixfield id="003">"DLC"</fixfield>

      <fixfield id="005">"20000104155648.0"</fixfield>

      <fixfield id="007">"cr||||"</fixfield>

      <fixfield id="007">"aj|aanzn"</fixfield>

      <fixfield id="008">"980520s1850    nyu       a     0   eng  "</fixfield>

      <varfield id="035" i1=" " i2=" ">

        <subfield label="9">(DLC)   98688713</subfield>

      </varfield>

      <varfield id="035" i1=" " i2=" ">

        <subfield label="a">(DLC)5572293</subfield>

      </varfield>

      <varfield id="010" i1=" " i2=" ">

        <subfield label="a">   98688713 </subfield>

      </varfield>

      <varfield id="040" i1=" " i2=" ">

        <subfield label="a">DLC</subfield>

        <subfield label="c">DLC</subfield>

        <subfield label="d">DLC</subfield>

      </varfield>

      <varfield id="050" i1="0" i2="0">

        <subfield label="a">G3711.P3 1850</subfield>

        <subfield label="b">.J4</subfield>

        <subfield label="u">RR 462</subfield>

      </varfield>

      <varfield id="052" i1=" " i2=" ">

        <subfield label="a">3711</subfield>

      </varfield>

      <varfield id="072" i1=" " i2="7">

        <subfield label="a">P3</subfield>

        <subfield label="2">lcg</subfield>

      </varfield>

      <varfield id="100" i1="1" i2=" ">

        <subfield label="a">Jervis, John B.</subfield>

        <subfield label="q">(John Bloomfield),</subfield>

        <subfield label="d">1795-1885.</subfield>

      </varfield>

      <varfield id="245" i1="1" i2="0">

        <subfield label="a">Skeleton map, showing the position and 
                   connections of the Michigan Southern Rail Road 
                   (from Toledo to Chicago) with the several great 
                   rail road routes to the Atlantic seaboard and 
                   New York City via the south shore of Lake Erie.
                   </subfield>

      </varfield>

      <varfield id="260" i1=" " i2=" ">

        <subfield label="a">N[ew] Y[ork],</subfield>

        <subfield label="c">1850.</subfield>

      </varfield>

      <varfield id="300" i1=" " i2=" ">

        <subfield label="a">map</subfield>

        <subfield label="c">22 x 51 cm.</subfield>

      </varfield>

      <varfield id="507" i1=" " i2=" ">

        <subfield label="a">Scale ca. 1:3,000,000.</subfield>

      </varfield>

      <varfield id="510" i1="4" i2=" ">

        <subfield label="a">LC Railroad maps,</subfield>

        <subfield label="c">462</subfield>

      </varfield>

      <varfield id="500" i1=" " i2=" ">

        <subfield label="a">Description derived from published 
                  bibliography.</subfield>

      </varfield>

      <varfield id="520" i1=" " i2=" ">

        <subfield label="a">Outline map of the northeastern 
            United States showing railroads in operation, 
            under construction, and under proposal. Chartered 
            in 1846 and consolidated April 1855 with the Northern 
            Indiana Railroad under the name Michigan Southern and 
            Northern Indiana Railroad.</subfield>

      </varfield>

      <varfield id="530" i1=" " i2=" ">

        <subfield label="a">Available also through the Library 
            of Congress Web site as a raster image.</subfield>

      </varfield>

      <varfield id="610" i1="2" i2="0">

        <subfield label="a">Michigan Southern Railroad</subfield>

        <subfield label="v">Maps.</subfield>

      </varfield>

      <varfield id="650" i1=" " i2="0">

        <subfield label="a">Railroads</subfield>

        <subfield label="z">Northeastern States</subfield>

        <subfield label="v">Maps.</subfield>

      </varfield>

      <varfield id="752" i1=" " i2=" ">

        <subfield label="a">United States</subfield>

        <subfield label="c">Northeastern States.</subfield>

      </varfield>

      <varfield id="710" i1="2" i2=" ">

        <subfield label="a">Michigan Southern Railroad.</subfield>

      </varfield>

      <varfield id="852" i1="0" i2=" ">

        <subfield label="a">Library of Congress</subfield>

        <subfield label="b">Geography and Map Division</subfield>

        <subfield label="e">Washington, D.C. 20540-4650 USA</subfield>

        <subfield label="n">dcu</subfield>

      </varfield>

      <varfield id="856" i1="7" i2=" ">

        <subfield label="d">g3711p</subfield>

        <subfield label="f">rr004620</subfield>

        <subfield label="g">urn:hdl:loc.gmd/g3711p.rr004620</subfield>

        <subfield label="u">http://hdl.loc.gov/loc.gmd/g3711p.rr004620</subfield>

        <subfield label="2">http</subfield>

      </varfield>

    </oai_marc>

  </metadata>

 </record>

</GetRecord> 

Appendix 2: Sample XML Schemas for the description part
of a reply to Identify request

The response to an Identify request may contain a list of description containers, which provide an extensible mechanism for communities to describe their repositories.  Each description container must be accompanied by the URL of an XML schema, which provides the semantics of the container.   XML Schemas for two examples of description containers are given below:

• The oai-identifier which is used by repositories that choose to comply with a specific format of unique identifiers for records. The format of that identifier is explained by means of comments in the oai-identifier.xsd XML Schema.
• The eprints container which has been agreed upon by the OAI e-print community. The container is used to describe content and policy properties of repositories in the e-print community.

<schema xmlns="http://www.w3.org/2001/XMLSchema"
           xmlns:oai-identifier="http://www.openarchives.org/OAI/1.1/oai-identifier"
           targetNamespace="http://www.openarchives.org/OAI/1.1/oai-identifier"
           elementFormDefault="qualified"
           attributeFormDefault="unqualified">

    <annotation>
     <documentation>
      Schema for description section of Identify reply, for repositories 
         that comply with the oai format for unique identifiers for records.
      the Open Archives Initiative. 2000. 
      Validated at http://www.w3.org/2001/03/webdata/xsv on 05-09-2001.
     </documentation>
    </annotation>

  <element name="oai-identifier" type="oai-identifier:oai-identifierType"/>

  <complexType name="oai-identifierType">
   <sequence>
    <!--    ....   -->
    <!-- Repositories that comply to the OAI format of unique record -->
    <!-- identifiers, use unique identifiers that are the concatenation of: -->
    <!--    * A "scheme" that must be equal to oai -->
    <!--    * A "repositoryIdentifier" that is a unique identifier for a -->
    <!-- repository.  Its uniqueness will be tested as part of a -->
    <!-- registration process.  The repositoryIdentifier is case -->
    <!-- sensitive and may contain the characters [a-z]|[A-Z]|[0-9] -->
    <!-- e.g. arXiv, VTETD. 
    <!--    * A local identifier that is the unique identifier of a record -->
    <!-- within a repository -->
    <!--    * These three parts must be concatenated using a "delimiter" -->
    <!-- which must be a colon.   -->
    <!--    ....   -->
    <element name="scheme" minOccurs="1" maxOccurs="1" fixed="oai"/>
    <element name="repositoryIdentifier" minOccurs="1" maxOccurs="1" 
             type="oai-identifier:repositoryIdentifierType"/>
    <element name="delimiter" minOccurs="1" maxOccurs="1" fixed=":"/>
    <!--    ....   -->
    <!-- "sampleIdentifier" : A sample identifier from the repository, -->
    <!-- e.g. oai:arXiv:hep-th/9901001 , oai:VTETD:etd-3345131939761081 -->
    <!--    ....   -->
    <element name="sampleIdentifier" minOccurs="1" maxOccurs="1" 
             type="oai-identifier:IdentifierType"/>
   </sequence>
  </complexType>

  <simpleType name="repositoryIdentifierType">
   <restriction base="string">
     <pattern value="[a-zA-Z0-9]+"/>
   </restriction>
  </simpleType>

  <simpleType name="IdentifierType">
   <restriction base="string">
     <pattern value="oai:[a-zA-Z0-9]+:.*"/>
   </restriction>
  </simpleType>

   </schema>

Examples

<oai-identifier xmlns="http://www.openarchives.org/OAI/1.1/oai-identifier"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

     xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/oai-identifier         

                   http://www.openarchives.org/OAI/1.1/oai-identifier.xsd">
<scheme>oai</scheme> 

<repositoryIdentifier>bespa</repositoryIdentifier>    

<delimiter>:</delimiter> 

<sampleIdentifier>oai:bespa:medi99-123</sampleIdentifier>

</oai-identifier> 

<schema xmlns="http://www.w3.org/2001/XMLSchema"
           xmlns:eprints="http://www.openarchives.org/OAI/1.1/eprints"
           targetNamespace="http://www.openarchives.org/OAI/1.1/eprints"
           elementFormDefault="qualified"
           attributeFormDefault="unqualified">

    <annotation>
     <documentation>
      Schema for description section of Identify reply, defined by 
      the e-print community.
      the Open Archives Initiative. 2000. 
      Validated at http://www.w3.org/2001/webdata/xsv on 05-09-2001.
     </documentation>
    </annotation>

  <element name="eprints" type="eprints:eprintsDescriptionType"/>

  <complexType name="eprintsDescriptionType">
   <sequence>
    <!--    ....   -->
    <!-- "content" : Text and/or a URL linking to text describing the -->
    <!-- content of the repository.     -->
    <!-- It would be appropriate to indicate the language(s) -->
    <!-- of the metadata/data in the repository. -->
    <!--    ....   -->
    <element name="content"  minOccurs="0" maxOccurs="1" 
             type="eprints:TextURLType"/>
    <!--    ....   -->
    <!-- "metadataPolicy" : Text and/or a URL linking to text describing -->
    <!-- policies relating to the use of metadata  -->  
    <!-- harvested through the OAI interface.  -->  
    <!--    ....   -->   
    <element name="metadataPolicy"  minOccurs="1" maxOccurs="1" 
             type="eprints:TextURLType"/>
    <!--    ....   -->
    <!-- "dataPolicy" : Text and/or a URL linking to text describing -->
    <!-- policies relating to the data  held in the -->
    <!-- repository.  This may also describe policies -->
    <!-- regarding downloading data (full-content). -->  
    <!--    ....   -->  
    <element name="dataPolicy"  minOccurs="1" maxOccurs="1" 
             type="eprints:TextURLType"/>
    <!--    ....   -->
    <!-- "submissionPolicy" : -->
    <!-- Text and/or a URL linking to text describing -->
    <!-- policies relating to the submission of content -->
    <!-- to the repository (or other accession mechanisms).  -->  
    <!--    ....   -->  
    <element name="submissionPolicy"  minOccurs="0" maxOccurs="1" 
             type="eprints:TextURLType"/>
    <!--    ....   -->  
    <!-- "comment" : -->
    <!-- Text and/or a URL linking to text describing anything -->
    <!-- else that is not covered by the fields above. -->
    <!-- It would be appropriate to include additional -->  
    <!-- contact details (additional to the adminEmail -->
    <!-- that is part of the response to the Identify request). -->  
    <!--    ....   --> 
    <element name="comment"  minOccurs="0" maxOccurs="unbounded" 
             type="string"/>
   </sequence>
  </complexType>
 <complexType name = "TextURLType" > 
  <choice minOccurs="0" maxOccurs="unbounded">
    <element name="URL" minOccurs="0" maxOccurs="unbounded" type="anyURI"/>
    <element name="text" minOccurs="0" maxOccurs="unbounded" type="string"/>
  </choice>
  </complexType>

   </schema>

Examples

<eprints xmlns="http://www.openarchives.org/OAI/1.1/eprints"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xsi:schemaLocation="http://www.openarchives.org/OAI/1.1/eprints         

    http://www.openarchives.org/OAI/1.1/eprints.xsd">
  <content>

     <URL>http://arXiv.org/arXiv_content.htm</URL>

  </content>

  <metadataPolicy>

     <text>Metadata can be used by commercial and non-commercial 
           service providers</text>

     <URL>http://arXiv.org/arXiv_metadata_use.htm</URL>

  </metadataPolicy>

  <dataPolicy>

     <text>Full content, i.e. preprints may not be harvested by robots</text>

  </dataPolicy>

  <submissionPolicy>

     <URL>http://arXiv.org/arXiv_submission.htm</URL>

  </submissionPolicy>

</eprints>

Acknowledgements

Support for the compilation of this document and for other Open Archives Initiative activities comes from the Digital Library Federation and the Coalition for Networked Information. Additional support for work on Open Archives Initiatives protocols comes from National Science Foundation Grant No. IIS-9817416 and Defense Advanced Projects Agency Grant No. N66001-98-1-8908.

Many thanks to the alpha testing group and the participants at the Cornell technical meeting: <caar@loc.gov> Caroline Arms -- <dih1@cornell.edu> Diane Hillmann -- <dsm@columbia.edu> David Millman -- <dstuve@mit.edu> David Stuve -- <dwoo@loc.gov> Dave Woodward -- <herbertv@cs.cornell.edu> Herbert Van de Sompel -- <hickey@oclc.org> Thom Hickey -- <hussein@vt.edu> Hussein Suleman -- <john.ober@ucop.edu> John Ober -- <jperkins@fox.nstn.ca> John Perkins -- <lagoze@cs.cornell.edu> Carl Lagoze -- <lisap@ukoln.ac.uk> Andy Powell -- <liu_x@cs.odu.edu> Xiaoming Liu -- <lloyd@aztec.lib.utk.edu> Jim Lloyd -- <mln@ils.unc.edu> Michael Nelson -- <mcundiff@loc.gov> Morgan V. Cundiff -- <oren@exlibris-usa.com> Oren Beit-Arie -- <rden@loc.gov> Ray Dennenberg -- <rht96r@ecs.soton.ac.uk> Rob Tansley -- <rjm2@cornell.edu> Rich Marisa -- <rstevenson@accesscable.net> Rob Stevenson -- <sb@ldc.upenn.edu> Steven Bird -- <schwander@pion.lanl.gov> Thorsten Schwander -- <simeon@lanl.gov> Simeon Warner -- <t-cole3@uiuc.edu> Tim Cole -- <T.Krichel@surrey.ac.uk> Thomas Krichel -- <thabing@uiuc.edu> Tom Habing -- <support@eprints.org> Christopher Gutteridge -- <jyoung@oclc.org> Jeff Young -- <stern@cs.dal.ca> Henry Stern.

Very special thanks for playing a distinct enabling role to: <hussein@vt.edu> Hussein Suleman -- <mln@ils.unc.edu> Michael Nelson -- <simeon@lanl.gov> Simeon Warner

Document History

2001-08-07: Modified "oai_marc.xsd", "eprints.xsd", and "oai-identifier.xsd" to fix some whitespace problems and to make some attribute improvements. The changes are are complements of Hussein Suleman (and any typos are Donna Bergmark's).

2001-06-20: Released protocol version 1.1. Changes were made to every .xsd file as well as to all the examples. This version is compliant with the May, 2001 W3C XML Schema recommendation.

2001-04-24: Made changes to GetRecord.xsd , ListRecords.xsd and ListIdentifiers.xsd regarding the specification of the "status" attribute that can be used with a record. "status" was specified with use="fixed" and value="deleted", which caused parsers to use "deleted" as a default. The correction specifies "status" as "optional" and restricts it to be of statusType, which can only have one value being "deleted".

2001-04-06: Added occurency specification -- minOccurs="0" maxOccurs="1" -- to the aboutType in GetRecord.xsd and ListRecords.xsd .

2001-02-23: Corrected an error in ListMetadataFormats.xsd. The root element was listed as ListMetdata instead of ListMetadataFormats.