Existing MetaData

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Contents

Introduction

Metadata is the information used to describe schemas and elements, such as attributes, of schemas. Most identity systems that have extensible schema implement a few types of metadata. Some of these are mandatory, without which the schema cannot be understood by the identity system. There is also metadata on identity schema which is not implemented by identity systems themselves, but is descriptive and is useful for architects and schema designers.

Identity Systems with metadata of interest include:

Related documents:

1. Combined informal metadata table

This table merges the mandatory and optional metadata of each identity system, as well as metadata that is identity system independent.

1.1. Metadata of schema elements

Element RDF Property Used By Purpose Syntax Comment Proposer
application domain of applicability TBD N/A App Development URI for schemas which are intended for use within a particular application domain, e.g. "PKI". Mark Wahl
canonical XRI TBD XRI/XDI See above XRI Of the set of XRI synonyms for an XDI dictionary entry, this is the recommended primary foreign key (typically a persistent XRI without human semantics) Drummond Reed
deprecation TBD LDAP Id System Operations boolean or date-of-deprecation Allow a schema owner to mark that a schema element is deprecated and new instances should not use that schema Mark Wahl
document link TBD N/A App Development language, media type and URI links to a document in a format such as HTML or PDF that describes the schema in human-readable terms MarkWahl
ldap name TBD LDAP, SPMLv2/DSML Id System Operations letters, digits, hyphen,period Provide identifier for attribute or object class: Each LDAP attribute or object class needs a type name or OID MarkWahl
metadata URI TBD N/A Schema mapping URIs, but might need more - see next line list of resolvable URIs at which there are documents containing this metadata for a particular schema element MarkWahl
metadata document type TBD N/A Schema mapping TBD specification of the media type and schema of the documents at the end of each of the metadata URI (e.g. what RDF dialect is being used - H-OWL, RDFX, Schemat, etc) MarkWahl
organizational domain of applicability TBD N/A App Development URI for schemas which are created and intended for use only with a single organization MarkWahl
trademark TBD FOAF App Development text e.g. on the foaf:myersBriggs attribute may wish to mention that Myers Briggs Type Indicator and MBTI are registered trademarks of X, and Y has exclusive rights to the trademark in the UK. MarkWahl
XRI TBD XRI/XDI Identification, addressing, & metadata discovery XRI In an XDI dictionary, each entry has one or more XRI synonyms DrummondReed

 

1.2. Metadata of attribute types

Element RDF Property Used By Purpose Syntax Comment Proposer
acquisition http://schema.openid.net/metadata#acquisition OpenID AX deployment URLs acquisition (where to get) DickHardt
assertion ID TBD SAML 2.0 Id System Operations XML ID MarkWahl
attribute URI TBD OpenID AX Id System Operations URI identifier for the attribute MarkWahl
attribute name format TBD SAML 2.0 Id System Operations URI classification of attribute name, for example urn:oasis:names:tc:SAML:2.0:attrname-format:uri MarkWahl
attribute name TBD SAML 2.0 Id System Operations see SAML 2.0 name of the attribute MarkWahl
authority http://schema.openid.net/metadata#authority OpenID AX deployment URLs authority (who can state) DickHardt
blob value restrictions TBD N/A Id System Operations TBD, perhaps a media type Further restrictions that a non-string value can have, such as a media type of image MarkWahl
cacheTTL TBD CARML Deployment days, hours, minutes, seconds Oracle IGF
cardinality within an entry TBD LDAP, Higgins, OpenID Id System Operations positive integer Number of possible values an attribute can have. LDAP has single vs multi-valued, others might have a specific maximum number of values DavidRecordon and PaulTrevithick
cluster TBD N/A Display TBD, perhaps a string keyword Cluster related attributes (e.g. 'home' address and phone number attributes should be kept distinct from 'work' address and phone number attributes). MarkWahl
comment http://www.w3.org/2000/01/rdf-schema#comment all Schema mapping language-tagged strings human friendly comment DavidRecordon and PaulTrevithick
decoder TBD FOAF App Development TBD, perhaps URI e.g. a foaf:geekCode can be converted to text by a Geek-Code-decoding application http://www.ebb.org/ungeek/ MarkWahl
display data http://www.eclipse.org/higgins/ontologies/2006/higgins#displayData Higgins Display Resource URI PaulTrevithick
display order predecessor TBD N/A Display TBD Specify the display order for attributes in a cluster (e.g. that in a name, the givenname comes before the middleInitial, and the middleInitial comes before the surname) MarkWahl
display order successor TBD N/A Display TBD Specify the display order for attributes in a cluster (e.g. that in a name, the givenname comes before the middleInitial, and the middleInitial comes before the surname) MarkWahl
domain http://www.w3.org/2000/01/rdf-schema#domain FOAF App Development URI of OWL class e.g. a foaf:accountName has domain foaf:OnlineAccount MarkWahl
embedded TBD N/A Display TBD link to attribute a givenName value may be embedded in a commonName value MarkWahl
encoding TBD LDAP, vCard Id System Operations keyword such as "b" or "base64", or URI even if the syntax is "String", is it because there is a transfer encoding, such as Base64 MarkWahl
equality matching rule TBD LDAP Id System Operations LDAP uses an OID to reference a function How to compare two values for equality? MarkWahl
equivalent attribute http://www.w3.org/2002/07/owl#equivalentClass Higgins Schema design PaulTrevithick
example http://schema.openid.net/metadata#example OpenID AX Application development any value human friendly example value DickHardt
friendly name TBD SAML 2.0 Id System Operations string friendly name of the attribute MarkWahl
label http://www.w3.org/2000/01/rdf-schema#label all Display language-tagged strings Internationalized human friendly display string/label DavidRecordon and PaulTrevithick
legal use ref TBD CARML Deployment URL representing legal documentation for how the information will be used. Oracle IGF
locale TBD LDAP, vCard Display locale name for attributes that are tied to a particular locale MarkWahl
may propogate TBD CARML Deployment boolean+parties list Oracle IGF
modifiable TBD CARML Deployment boolean Oracle IGF
owl type TBD FOAF App Development URI of OWL element e.g. a foaf:aimChatID is an OWL InverseFunctionalProperty (uniquely identifying property) MarkWahl
parameters TBD LDAP, vCard Id System Operations TBD what parameters an attribute can have, e.g. userCertificate can have ";binary"; description can have lang; vCard photo can have any IANA registered image format MarkWahl
pre-hash normalization function TBD N/A Id System Operations TBD, perhaps a URI to name a function How to create a byte array by normalizing a value (e.g. by upcase, remove spaces) so that all values which match for equality have the same resulting byte array MarkWahl
quality statement TBD CARML Deployment URL pointer to a document about the quality of verifiability of information requested. Oracle IGF
range http://www.w3.org/2000/01/rdf-schema#range FOAF App Development URI e.g. a foaf:accountName has range http://www.w3.org/2000/01/rdf-schema#Literal MarkWahl
references TBD Higgins Schema mapping TBD References to other seantically equivalent attributes, e.g. rdfs sellAlso and OWL's equivalentClass DavidRecordon and PaulTrevithick
required TBD Infocard Id System Operations boolean TBD MarkWahl
sample code TBD FOAF App Development probably URI e.g. a foaf:mbox_sha1sum may have metadata with a link to a program code in C, Java, Ruby, PHP that generates this MarkWahl
seeAlso http://www.w3.org/2000/01/rdf-schema#seeAlso OpenID AX Application development URLs additional information DickHardt
sensitivity TBD N/A Display TBD attributes which are known to be sensitive and may not be suitable for display by default, such as "userPassword", "SSN", or elements that are personal private such as health status Mark Wahl
stability TBD FOAF App Development unstable, testing and stable Stability of the schema element MarkWahl
string value restrictions TBD LDAP, Higgins, OpenID Id System Operations TBD, perhaps XML schema or BNF Further restrictions that a (string) value can have, such as maximum length. (MaximumLength is desirable for OpenID) DavidRecordon and PaulTrevithick
supertype http://www.w3.org/2000/01/rdf-schema#subClassOf LDAP, Higgins Id System Operations Attribute type identifier Specify the supertype for a particular type (e.g., that "surname", "givenName" are subtypes of "name"). MarkWahl
syntax TBD all Id System Operations various The syntax of values of the attribute DavidRecordon and PaulTrevithick
value ordering rule TBD LDAP Display LDAP uses an OID to reference a function How to sort two values to put them in order MarkWahl

 

1.3. Metadata of schema elements other than attributes

Element RDF Property Used By Purpose Syntax Comment Proposer
contributor, coverage, creator, date, description, format, identifier, language, publisher, relation, rights, source, subject, title, type Schema-as-a-whole N/A Descriptive various Dublin Core Metadata Element Set 1.1 MarkWahl
abstract, accessRights, accuralMethod, accrualPeriodicity, accrualPolicy, alternative, audience, available, bibliographicCitation, conformsTo, created, dateAccepted, dateCopyrighted, dateSubmitted, educationLevel, extent, hasFormat, hasPart, hasVersion, instructionalMethod, isFormatOf, isPartOf, isReferencedBy, isReplacedBy, isRequiredBy, issued, isVersionOf, license, mediator, medium, modified, provenance, references, replaces, requires, rightsHolder, spatial, tableOfContents, temporal, valid Schema-as-a-whole N/A Descriptive various Dublin Core Additional Metadata Terms MarkWahl
entry ordering rule and sort key Objectclass N/A Display TBD, perhaps a reference to an attribute and a URI to name a function How to sort to entries to put them in order - what attribute is the sort key MarkWahl
License style Schema-as-a-whole N/A App Development TBD, perhaps URI or keyword link to the license that governs the schema (e.g. BCP 78) MarkWahl
Superclass Objectclass LDAP Id System Operations Object class identifier Specify the superclass for a particular object class (e.g. that "inetOrgPerson" inherits from "organizationalPerson"). MarkWahl
Superschema Schema-as-a-whole LDAP Id System Operations TBD, perhaps a URL in place of the LDAPEXT OID Specify the schemas on which this schema depends (e.g. that a particular organization's schema is dependent on a standard schema) MarkWahl
kind Objectclass LDAP Id System Operations ABSTRACT, AUXILIARY or STRUCTURAL what kind of objectclass is this MarkWahl
name form Schema-as-a-whole X.500 Id System Operations Name Form Description when constructing entries, what object classes should be used MarkWahl
Contact name Schema-as-a-whole N/A App Development who to contact for more information MarkWahl
Contact info Schema-as-a-whole N/A App Development URI, probably an email address who to contact for more information MarkWahl
in Range of Objectclass FOAF App Development URI of RDF predicate e.g. a foaf:Person is in the range of foaf:knows MarkWahl
in Domain of Objectclass FOAF App Development URI of RDF predicate e.g. a foaf:Group is in the domain of foaf:member MarkWahl
required attributes Objectclass LDAP and SPMLv2/DSML Id System Operations attribute type names list of required attributes of object class MarkWahl
optional attributes Objectclass LDAP and SPMLv2/DSML Id System Operations attribute type names list of optional attributes of object class MarkWahl

 

2. Supporting tables

These tables are to help with building the above table and then turning it into one or more formal representations.

2.1. Mandatory-To-Implement metadata in each identity system

This table lists the metadata which is required to express a schema element in a particular identity system. If this metadata is not present for an attribute, then that attribute can't be represented correctly in a particular identity system. Being able to support these is necessary for identity schema mapping.

ID System Element On schema element(s) Syntax Comment
OpenID AX http://www.w3.org/1999/02/22-rdf-syntax-ns#type Attribute the XML Schema data type or a type defined as per Section 3.1 (Data Format Types) of OpenID AX Attribute Metadata
OpenID AX http://www.w3.org/2000/01/rdf-schema#label Attribute string with xml:lang The label is a short description of the attribute type.
OpenID AX http://www.w3.org/2000/01/rdf-schema#comment Attribute string with xml:lang The rdfs:comment element is used to provide a long textual description of the attribute type
LDAP and SPMLv2/DSML Name Attribute and Objectclass letters, digits, hyphen, period Each LDAP attribute and object class needs a type name or OID
LDAP Syntax Attribute OID of syntax The identifier of the syntax of this attribute
LDAP and SPMLv2/DSML Required attributes Objectclass list of attribute types The required attributes of a particular object class
LDAP and SPMLv2/DSML Optional attributes Objectclass list of attribute types The optional attributes of a particular object class

 

2.2. Metadata in RDF

This table lists the metadata from section 1 which already have representation as RDF predicates.

Metadata name Predicate Object Defined by
contributor, coverage, creator, date, description, format, identifier, language, publisher, relation, rights, source, subject, title, type various various Dublin Core Metadata Element Set 1.1
abstract, accessRights, accuralMethod, accrualPeriodicity, accrualPolicy, alternative, audience, available, bibliographicCitation, conformsTo, created, dateAccepted, dateCopyrighted, dateSubmitted, educationLevel, extent, hasFormat, hasPart, hasVersion, instructionalMethod, isFormatOf, isPartOf, isReferencedBy, isReplacedBy, isRequiredBy, issued, isVersionOf, license, mediator, medium, modified, provenance, references, replaces, requires, rightsHolder, spatial, tableOfContents, temporal, valid various various Dublin Core Additional Metadata Terms
N/A http://www.w3.org/1999/02/22-rdf-syntax-ns#type OpenID AX

 

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