Matrix defining the KEV ContextObject Format


dc:title KEV ContextObject Format
dc:creator NISO Committee AX
dc:description This Matrix represents the ContextObject as a string of ampersand-delimited Key/Encoded-Value pairs
dc:identifier info:ofi/fmt:kev:mtx:ctx
dcterms:created 2004-01-01
dcterms:modified

A representation of a Key/Encoded-Value pair is generated by concatenating the contents of the first four columns of a row that begins with an ampersand in the Matrix below. The ordering of KEV pairs is not important. Rows which have '#' in the first column are comments and should not be included in the representation.

The following data types are provided for the values of the Keys, which must be URL-encoded:

<data> Character string
<id> Character string for an Identifier (Z39.88-2004, Part 1, Section 7)
<fmt-id> Character string for a Format Identifier (Z39.88-2004, Part 1, Sections 12 and 13)
<m-key> Character string for a Metadata Key (Z39.88-2004, Part 2, Section 7.1)
<url> Character string for a URL
<date> Character string representing a date to the complete date level of the W3CDTF profile of ISO 8601, of the form: [ YYYY-MM-DD | YYYY-MM | YYYY ]
<time> Character string representing a date and time to the seconds level of the W3CDTF profile of ISO 8601, of the form: [ YYYY-MM-DDThh:mm:ssTZD | YYYY-MM-DD ]

Abbreviations in column headings:

The Matrix

Delim Key Equals Value Min Max Description
# ctx_ 0 1 Administration. As Admin is an optional field in a ContextObject, any of the keys with prefix ctx_ may be present
& ctx_ver = Z39.88-2004 0 1 ContextObject version. This has a fixed value
& ctx_enc = <data> 0 1 ContextObject encoding. The value for ctx_enc specifies the character encoding used in the ContextObject. Legitimate values are taken from the IANA list at http://www.iana.org/assignments/character-sets. The values to be used in the ContextObject are those listed next to Name or - if available - the values with an indication of 'preferred MIME name' in the IANA list. UTF-8 is the default value, representing UTF-8 encoded Unicode.
& ctx_id = <data> 0 1 ContextObject Identifier
& ctx_tim = <time> 0 1 ContextObject timestamp. YYYY-MM-DD or YYYY-MM-DDThh:mm:ssTZD
# rft_ 1 1 Referent. As Referent is a mandatory Entity in a ContextObject, at least one of the keys with prefix rft_ must be present
& rft_id = <id> 0 * Referent Identifier. Multiple instances of rft_id do not indicate multiple Referents, but rather multiple ways to identify a single Referent
& rft_val_fmt = <fmt-id> 0 1 Identifier of By-Value Metadata Format for a Referent. Identifier of the Metadata Format used for the description of the Referent through By-Value Metadata
# rft_val = 0 0 Reserved for future use
& rft.<m-key> = <data> 0 * By-Value Metadata Key for a Referent. The <m-key> is a Key defined in the KEV Metadata Format specified by the Value of the rft_val_fmt Key, which must be present. Use of the rft prefix is mandatory
& rft_ref_fmt = <fmt-id> 0 1 By-Reference Metadata Format for a Referent. The rft_ref Key must also be present
& rft_ref = <url> 0 1 By-Reference Metadata Location for a Referent. The rft_ref_fmt Key must also be present. The Resolver should retrieve the Metadata from the specified location
& rft_dat = <data> 0 1 Referent Private Data
# rfe_ 0 1 ReferringEntity. As ReferringEntity is an optional Entity in a ContextObject, any of the keys with prefix rfe_ may be present
& rfe_id = <id> 0 * ReferringEntity Identifier. Multiple instances of rfe_id do not indicate multiple ReferringEntities, but rather multiple ways to identify a single ReferringEntity
& rfe_val_fmt = <fmt-id> 0 1 Identifier of By-Value Metadata Format for a ReferringEntity. Identifier of the Metadata Format used for the description of the ReferringEntity through By-Value Metadata
# rfe_val = 0 0 Reserved for future use
& rfe.<m-key> = <data> 0 * By-Value Metadata Key for a ReferringEntity. The <m-key> is a Key defined in the KEV Metadata Format specified by the Value of the rfe_val_fmt Key, which must be present. Use of the rfe prefix is mandatory
& rfe_ref_fmt = <fmt-id> 0 1 By-Reference Metadata Format for a ReferringEntity. The rfe_ref Key must also be present
& rfe_ref = <url> 0 1 By-Reference Metadata Location for a ReferringEntity. The rfe_ref_fmt Key must also be present. The Resolver should retrieve the Metadata from the specified location
& rfe_dat = <data> 0 1 ReferringEntity Private Data
# req_ 0 1 Requester. As Requester is an optional Entity in a ContextObject, any of the keys with prefix req_ may be present
& req_id = <id> 0 * Requester Identifier. Multiple instances of req_id do not indicate multiple Requesters, but rather multiple ways to identify a single Requester
& req_val_fmt = <fmt-id> 0 1 Identifier of By-Value Metadata Format for a Requester. Identifier of the Metadata Format used for the description of the Requester through By-Value Metadata
# req_val = 0 0 Reserved for future use
& req.<m-key> = <data> 0 * By-Value Metadata Key for a Requester. The <m-key> is a Key defined in the KEV Metadata Format specified by the Value of the req_val_fmt Key, which must be present. Use of the req prefix is mandatory
& req_ref_fmt = <fmt-id> 0 1 By-Reference Metadata Format for a Requester. The req_ref Key must also be present
& req_ref = <url> 0 1 By-Reference Metadata Location for a Requester. The req_ref_fmt Key must also be present. The Resolver should retrieve the Metadata from the specified location
& req_dat = <data> 0 1 Requester Private Data
# svc_ 0 1 ServiceType. As ServiceType is an optional Entity in a ContextObject, any of the keys with prefix svc_ may be present
& svc_id = <id> 0 * ServiceType Identifier. Multiple instances of svc_id do not indicate multiple ServiceTypes, but rather multiple ways to identify a single ServiceType
& svc_val_fmt = <fmt-id> 0 1 Identifier of By-Value Metadata Format for a ServiceType. Identifier of the Metadata Format used for the description of the ServiceType through By-Value Metadata
# svc_val = 0 0 Reserved for future use
& svc.<m-key> = <data> 0 * By-Value Metadata Key for a ServiceType. The <m-key> is a Key defined in the KEV Metadata Format specified by the Value of the svc_val_fmt Key, which must be present. Use of the svc prefix is mandatory
& svc_ref_fmt = <fmt-id> 0 1 By-Reference Metadata Format for a ServiceType. The svc_ref Key must also be present
& svc_ref = <url> 0 1 By-Reference Metadata Location for a ServiceType. The svc_ref_fmt Key must also be present. The Resolver should retrieve the Metadata from the specified location
& svc_dat = <data> 0 1 ServiceType Private Data
# res_ 0 1 Resolver. As Resolver is an optional Entity in a ContextObject, any of the keys with prefix res_ may be present
& res_id = <id> 0 * Resolver Identifier. Multiple instances of res_id do not indicate multiple Resolvers, but rather multiple ways to identify a single Resolver
& res_val_fmt = <fmt-id> 0 1 Identifier of By-Value Metadata Format for a Resolver. Identifier of the Metadata Format used for the description of the Resolver through By-Value Metadata
# res_val = 0 0 Reserved for future use
& res.<m-key> = <data> 0 * By-Value Metadata Key for a Resolver. The <m-key> is a Key defined in the KEV Metadata Format specified by the Value of the res_val_fmt Key, which must be present. Use of the res prefix is mandatory
& res_ref_fmt = <fmt-id> 0 1 By-Reference Metadata Format for a Resolver. The res_ref Key must also be present
& res_ref = <url> 0 1 By-Reference Metadata Location for a Resolver. The res_ref_fmt Key must also be present. The Metadata should be retrieved from the specified location
& res_dat = <data> 0 1 Resolver Private Data
# rfr_ 0 1 Referrer. As Referrer is an optional Entity in a ContextObject, any of the keys with prefix rfr_ may be present
& rfr_id = <id> 0 * Referrer Identifier. Multiple instances of rfr_id do not indicate multiple Referrers, but rather multiple ways to identify a single Referrer
& rfr_val_fmt = <fmt-id> 0 1 Identifier of By-Value Metadata Format for a Referrer. Identifier of the Metadata Format used for the description of the Referrer through By-Value Metadata
# rfr_val = 0 0 Reserved for future use
& rfr.<m-key> = <data> 0 * By-Value Metadata Key for a Referrer. The <m-key> is a Key defined in the KEV Metadata Format specified by the Value of the rfr_val_fmt Key, which must be present. Use of the rfr prefix is mandatory
& rfr_ref_fmt = <fmt-id> 0 1 By-Reference Metadata Format for a Referrer. The rfr_ref Key must also be present
& rft_ref = <url> 0 1 By-Reference Metadata Location for a Referrer. The rfr_ref_fmt Key must also be present. The Resolver should retrieve the Metadata from the specified location
& rfr_dat = <data> 0 1 Referrer Private Data

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