<idno>

<idno> (identifier) supplies any form of identifier used to identify some object, such as a bibliographic item, a person, a title, an organization, etc. in a standardized way. [13.3.1 Basic Principles 2.2.4 Publication, Distribution, Licensing, etc. 2.2.5 The Series Statement 3.12.2.4 Imprint, Size of a Document, and Reprint Information]
Module header — The TEI Header
Attributes
type⚓︎ categorizes the identifier, for example as an ISBN, Social Security number, etc.
Derived from att.typed
Status Optional
Datatype teidata.enumerated
Suggested values include:
ISBN
International Standard Book Number: a 13- or (if assigned prior to 2007) 10-digit identifying number assigned by the publishing industry to a published book or similar item, registered with the International ISBN Agency.
ISSN
International Standard Serial Number: an eight-digit number to uniquely identify a serial publication.
DOI
Digital Object Identifier: a unique string of letters and numbers assigned to an electronic document.
URI
Uniform Resource Identifier: a string of characters to uniquely identify a resource, following the syntax of RFC 3986.
VIAF
A data number in the Virtual Internet Authority File assigned to link different names in catalogs around the world for the same entity.
ESTC
English Short-Title Catalogue number: an identifying number assigned to a document in English printed in the British Isles or North America before 1801.
OCLC
OCLC control number (record number) for the union catalog record in WorldCat, a union catalog for member libraries in the Online Computer Library Center global cooperative.
calendar⚓︎ indicates one or more systems or calendars to which the date represented by the content of this element belongs.
Deprecated This feature will be withdrawn after 2024-11-11
Status Optional
Datatype 1–∞ occurrences of teidata.pointer separated by whitespace
Schematron

<sch:rule context="tei:*[@calendar]">
<sch:assert test="string-length( normalize-space(.) ) gt 0"> @calendar indicates one or more
systems or calendars to which the date represented by the content of this element belongs,
but this <sch:name/> element has no textual content.</sch:assert>
</sch:rule>
Member of
model.msItemPart model.nameLike model.personPart model.publicationStmtPart.detail
Contained by
analysis: cl phr s span
core: abbr add addrLine address analytic author bibl biblScope citedRange corr date del desc distinct editor email emph expan foreign gloss head headItem headLabel hi item l label measure meeting mentioned monogr name note num orig p pubPlace publisher q quote rb ref reg resp rs rt said series sic soCalled speaker stage street term textLang time title unclear unit
corpus: activity channel constitution derivation domain factuality interaction locale preparedness purpose
dictionaries: case colloc def dictScrap entryFree etym form gen gram gramGrp hyph iType lang lbl mood number orth per pos pron re sense stress subc syll tns usg xr
drama: actor camera caption castItem role roleDesc sound tech view
figures: cell figDesc
header: authority catDesc change classCode correspAction creation distributor edition extent funder geoDecl handNote idno language licence principal publicationStmt rendition scriptNote seriesStmt sponsor tagUsage
iso-fs: fDescr fsDescr
linking: ab seg
msdescription: accMat acquisition additions altIdentifier catchwords collation collection colophon condition custEvent decoNote explicit filiation finalRubric foliation heraldry incipit institution layout material msIdentifier msItem musicNotation objectType origDate origPlace origin provenance repository rubric secFol signatures source stamp summary support surrogates typeNote watermark
namesdates: addName affiliation age birth bloc country death district education event eventName faith floruit forename genName gender geogFeat geogName langKnown nameLink nationality nym objectIdentifier objectName occupation offset org orgName persName persPronouns person personGrp persona place placeName region residence roleName settlement sex socecStatus surname
spoken: u writing
tagdocs: eg moduleSpec valDesc
textcrit: lem rdg wit witDetail witness
textstructure: byline closer dateline docAuthor docDate docEdition docImprint imprimatur opener salute signed titlePart trailer
transcr: damage fw metamark mod restore retrace secl supplied surplus
verse: metSym rhyme
May contain
gaiji: g
header: idno
character data
Note

idno should be used for labels which identify an object or concept in a formal cataloguing system such as a database or an RDF store, or in a distributed system such as the World Wide Web. Some suggested values for type on idno are ISBN, ISSN, DOI, and URI.
Example
<idno type="ISBN">978-1-906964-22-1</idno>
<idno type="ISSN">0143-3385</idno>
<idno type="DOI">10.1000/123</idno>
<idno type="URI">http://www.worldcat.org/oclc/185922478</idno>
<idno type="URI">http://authority.nzetc.org/463/</idno>
<idno type="LT">Thomason Tract E.537(17)</idno>
<idno type="Wing">C695</idno>
<idno type="oldCat">
 <g ref="#sym"/>345
</idno>

In the last case, the identifier includes a non-Unicode character which is defined elsewhere by means of a glyph or char element referenced here as #sym.
Content model 
<content>
 <alternate minOccurs="0"
  maxOccurs="unbounded">
  <textNode/>
  <classRef key="model.gLike"/>
  <elementRef key="idno"/>
 </alternate>
</content>
Schema Declaration 
<rng:element name="idno">
 <rng:ref name="att.global.attributes"/>
 <rng:ref name="att.global.rendition.attributes"/>
 <rng:ref name="att.global.linking.attributes"/>
 <rng:ref name="att.global.analytic.attributes"/>
 <rng:ref name="att.global.facs.attributes"/>
 <rng:ref name="att.global.change.attributes"/>
 <rng:ref name="att.global.responsibility.attributes"/>
 <rng:ref name="att.global.source.attributes"/>
 <rng:ref name="att.sortable.attributes"/>
 <rng:ref name="att.datable.attributes"/>
 <rng:ref name="att.datable.w3c.attributes"/>
 <rng:ref name="att.datable.iso.attributes"/>
 <rng:ref name="att.datable.custom.attributes"/>
 <rng:ref name="att.typed.attribute.subtype"/>
 <rng:optional>
  <rng:attribute name="type">
   <rng:choice>
    <rng:value>ISBN</rng:value>
    <rng:value>ISSN</rng:value>
    <rng:value>DOI</rng:value>
    <rng:value>URI</rng:value>
    <rng:value>VIAF</rng:value>
    <rng:value>ESTC</rng:value>
    <rng:value>OCLC</rng:value>
    <rng:ref name="teidata.enumerated"/>
   </rng:choice>
  </rng:attribute>
 </rng:optional>
 <rng:optional>
  <rng:attribute name="calendar">
   <rng:list>
    <rng:oneOrMore>
     <rng:ref name="teidata.pointer"/>
    </rng:oneOrMore>
   </rng:list>
  </rng:attribute>
 </rng:optional>
 <rng:zeroOrMore>
  <rng:choice>
   <rng:text/>
   <rng:ref name="model.gLike"/>
   <rng:ref name="idno"/>
  </rng:choice>
 </rng:zeroOrMore>
</rng:element>
element idno
{
   att.global.attributes,
   att.global.rendition.attributes,
   att.global.linking.attributes,
   att.global.analytic.attributes,
   att.global.facs.attributes,
   att.global.change.attributes,
   att.global.responsibility.attributes,
   att.global.source.attributes,
   att.sortable.attributes,
   att.datable.attributes,
   att.datable.w3c.attributes,
   att.datable.iso.attributes,
   att.datable.custom.attributes,
   att.typed.attribute.subtype,
   attribute type
   {
      "ISBN"
    | "ISSN"
    | "DOI"
    | "URI"
    | "VIAF"
    | "ESTC"
    | "OCLC"
    | teidata.enumerated
   }?,
   attribute calendar { list { teidata.pointer+ } }?,
   ( text | model.gLike | idno )*
}