Correspondence Metadata Interchange format

Documentation

The CMIF is developed and documented by the TEI Correspondence SIG. The documentation below is an HTML converted version of the original version which is published under a CC BY 4.0 licence in the TEI Correspondence SIG's GitHub repository.

Introduction

The "Correspondence Metadata Interchange Format" (CMIF) enables scholars to create digital indexes of letters from their scholarly editions and provide them online. The CMIF has been developed by the TEI Correspondence SIG and is a highly reduced and restricted subset of the TEI Guidelines which is based mainly on the TEI element correspDesc.

The Basis of a digital index of letters according to the CMI format is a TEI-XML file. You can download templates with short descriptions here.

Overview

The TEI-XML file contains as many correspDesc elements as the provider have letters, postcards, etc. in his scholarly edition. A particular correspDesc element in CMI format is more restrictive and reduced with regard to its vocabulary than the TEI Guidlines generally allow. This enables interchange between the respective TEI documents.

The image shows schematically the different parts of a correspDesc element in the CMI format. The addressee and sender are documented the same way. The example originates from an example provided by the TEI Correspondence SIG.

For persons and places in the "correspondence description" (sender, addresssee, senders place etc.) an ID from an authority file should be provided to identify these entities across projects and to use the correspondence metadata in network analysis or web services (e.g. correspSearch). Possible authority files for persons could be:

For places the TEI Correspondence SIG recommends to use the free licensed geographical database GeoNames.

Details

Correspondence Metadata

The following table offers detailed information about the particular parts of a correspDesc element in the CMI format:

  • /@key
    Description

    Number or ID of the letter in the (printed or digital) scholarly edition. To note the number of the letter in @key is especially recommended for printed editions.

    Value(s) and Notes

    E.g. "128"

  • /@ref
    Description

    URL of the letter, if available online. The URL should be an official and permanent link. If different versions of a letter are available, a canonical link should be used.

    Value(s) and Notes

    E.g. "http://edition-humboldt.de/H0002656"

  • /@source
    Description

    Links with the help of an UUID (prefixed by "#") to the bibliographic information (i.e. where the correspondence metadata comes from). Form more information see bibl/@xml:id below.

    Value(s) and Notes

    E.g. "#c3f497f0-488d-4233-9448-130ba8109bd8"

  • /correspAction
    Description

    Includes the data related to the sending/receiving process of a letter, postcard etc.

    Value(s) and Notes

    Only the following child elements (no text allowed): persName, orgName, placeName, date

  • /correspAction/@type
    Description

    Type of the correspondence action.

    Value(s) and Notes

    Allowed: "sent", "received"

  • /correspAction/persName
    Description

    Personal name of sender or addressee.

    Value(s) and Notes

    Mandatory; if the sender or addressee is unknown please indicate this by the string "Unbekannt".

  • /correspAction/persName/@ref
    Description

    Authority controlled ID of sender or addressee.

    Value(s) and Notes

    Strongly recommended, if available. Possible authority files: VIAF, GND, LC, BNF and NDL (see above).

  • /correspAction/orgName
    Description

    Name of institution, company etc.

    Value(s) and Notes

    Optional, if PersName is not applicable.

  • /correspAction/placeName
    Description

    Name of the place a letter was sent from or where it is being sent to.

    Value(s) and Notes

    If available.

  • /correspAction/placeName/@ref
    Description

    Authority controlled ID of the place a letter was sent from or where it is being sent to.

    Value(s) and Notes

    Strongly recommended, if available. Possible authority files: GeoNames (see above).

  • /correspAction/date
    Description

    Machine-readable date of when the letter was sent or received.

    Value(s) and Notes

    If available. The CMIF supports the attributes @when, @from, @to, @notBefore und @notAfter. To facilitate the interchange, the CMIF supports (unlike the TEI Guidelines) only the following date formats:

    • YYYY-MM-DD, e.g. 1804-03-01
    • YYYY-MM, E.g. 1804-03
    • YYYY, E.g. 1808

The correspDesc elements are noted inside TEI/teiHeader/profileDesc - as described in the TEI Guidelines.

Information about the digital index of letters

Besides the correspondence metadata, the provider have to include some information about the CMIF file and the digital index of letters itself in the teiHeader/fileDesc element. All elements there are mandatory if not stated otherwise.

  • //titleStmt/title
    Description

    Title of the digital index of letters.

    Value(s) and Notes

    Free text field.

  • //titleStmt/editor
    Description

    Contact person concerning the digital index of letters.

    Value(s) and Notes

    If available with an e-mail address in editor/email.

  • //publicationStmt/publisher
    Description

    Originator of the letter metadata as defined in the Creative Commons Licence CC-BY 4.0.

    Value(s) and Notes

    Free text field.

  • //publicationStmt/availability/licence
    Description

    Licence statement.

    Value(s) and Notes

    Mandatory: "This file is licensed under the terms of the Creative Commons License CC-BY 4.0".

  • //publicationStmt/availability/licence/@target
    Description

    URL of the licence.

    Value(s) and Notes

    Mandatory: "https://creativecommons.org/licenses/by/4.0/".

  • //publicationStmt/date/@when
    Description

    Timestamp of the last update of this file.

    Value(s) and Notes

    Format: xsd:dateTime.

  • //publicationStmt/idno
    Description

    URL of this digital index of letters.

    Value(s) and Notes

    The URL serves as a unique identifier for the CMIF file and ensures that the file can always traced back to their origin.

  • //publicationStmt/idno/@type
    Description

    Type of the above mentioned identifier.

    Value(s) and Notes

    Mandatory: "URL" .

  • //sourceDesc/bibl
    Description

    Bibliographic information about the scholarly edition from which the correspondence metadata is derived from.

    Value(s) and Notes

    No specifications.

  • //sourceDesc/bibl/@xml:id
    Description

    Technical ID of the bibl element, i.e. the bibliographic information. An UUID have to be used. The correspDesc items have to be referenced by this UUID (see above @source).

    Value(s) and Notes

    E.g. "#c3f497f0-488d-4233-9448-130ba8109bd8". UUID can easily be generated by many online tools. If the CMIF is created via a script (as common in digital scholarly editions), it is recommended to use a "static" UUID, i.e. which is not re-generated every time the CMIF data is updated.

  • //sourceDesc/bibl/@type
    Description

    Type of scholarly edition.

    Value(s) and Notes

    The following values are allowed: "print", "online".

Any further questions?

For more information see the FAQ section.

Further information

You can find further examples of the CMI format on the GitHub repository of the TEI Correspondence SIG.

Future of the CMI format

A blog article on digiversity discusses the further development of the CMI format.