Step by step to a digital index of letters

… with the CMIF Creator

Every letter edition – whether printed or digitally published – can provide a digital index of letters in the “Correspondence Metadata Interchange Format” (CMIF) and register it with the web service correspSearch.

In order to create a CMIF file as easy as possible, you can use the provided CMIF Creator by correspSearch. net. The creation of a CMIF file using using the CMIF Creator is explained in detail below.


Call up the CMIF Creator and start a new digital index of letters by clicking on "Start".

Step 1: Metadata

In this step, enter information about the CMIF file you are currently editing. The following information must be provided:

  • Title of the CMIF file: The title can be freely chosen, but should not be too long. Example:"Correspondence Alexander von Humboldt / Varnhagen von Ense 1827-1848".
  • Creator of the CMIF file with first name and surname.
  • E-mail of the creator: As first contact for technical and content-related questions
  • Publisher of the CMIF file: Provider of the file or data, could also be an institution. This field is understood and used as the originator within the meaning of the CC-BY 4.0 license (see below).
  • Website of the publisher: It is particularly useful for institutions to include the official URL.
  • URL to the CMIF file: Enter the URL under which the CMIF file will be accessible later. This means that the file can always be traced back to its origin.
  • License: The file must be under a free Creative Commons license, so that the legally secure processing and subsequent use by correspSearch and other services and researchers is possible. Choose one of the two possible Creative Commons licenses:

Step 2: Bibliographic information

In this step, enter the bibliographic information of the publication for which you provide the index of letters or from which you take the metadata of the letters. If necessary, you can also enter several publications. Please note that in the case of a multi-volume series, each volume is to be recorded individually.

Step 3: Letter data sets

Here you enter the metadata of the editions of letters - that is, the sender*in, place of writing, date and addressee*in, place and date of receipt. A new data record is created for each letter. Fill in as much information as you know; if there is no information (such as the date of receipt) you can simply leave the corresponding fields blank. Tip: With the Tab key you can quickly jump to the next field. The particulars in detail:

  • Letter number: Here you enter the letter number if one has been assigned in the edition.
  • URL to the letter: If the edition is digitally available and a direct URL to the letter exists, you can enter it here.
  • In: Indicates the publication from which the letter data set originates or to which it refers. Is usually prefilled, unless you have specified several publications.

For every sender and recipient:

  • Name: in spelling First name Last name
  • Authority file ID from GND, VIAF etc.: If possible, an ID from an authority file should be entered here for each person. You must always enter not only the number but also the entire URI, e. g. Once you have entered a name the form will offer its authority file ID the next time you enter it.
  • Authority file ID from GeoNames: An ID from the free database "GeoNames" should be entered for each location. Once you have entered a name the form will offer its authority file ID the next time you enter it.
  • In order for the web service correspSearch and other programs to be able to evaluate the dates, these must be recorded in a machine-readable form. According to TEI guidelines, there are three date types:
    • Exact time, for example, March 14th, 1830.
    • Exact time span, e. g."04/03 to 07/04/1834"
    • Approximate period: "Summer 1838".

For all date types, a date in the format "YYYYY-MM-DD","YYYY-MM" or "YYYY" must be entered. All other data (e. g. 1808-03/04) cannot be processed technically. Therefore, these dates must be translated for the CMIF file.

Authority File IDs for persons and places

The web service does not use their names to search for persons and places, since they can occur in several variants (spelling, non-uniform first names) as well as being ambiguous ("Peter Müller"). Rather, the search is based on cross-project IDs from standard files, such as the Common Standard File of the German National Library. For this reason, a standard ID should be recorded in the digital letter list for each person or location. The web service currently supports the following standard files for people:

  • GND: Common standard file of the German National Library
  • VIAF: Virtual Authority File
  • BNF: Authorités of the Bibliothèque nationale de France (BNF)
  • LC: Library of Congress
  • NDL: National Diet Library, Japan

For the German-speaking countries, it is advisable to search first in the GND. In addition to the search of the German National Library, it is also possible to search via "Online-GND" (OGND) of the Bibliotheksservice-Zentrum Baden-Württemberg. The interface of the OGND offers partly more comfortable possibilities to search for a specific person. It is recommended to set the search key of "Teilwortsuche[SW]" to "Person (Phrase: Nachname, Vorname)[PER]" in the OGND. If the search result is not satisfactory, you may want to reduce the first names or use the search key "person (Stichwort)[PST]".

If a person is not found in the GND, you can search for a standard ID via the Virtual International Authority File.

The locations are recorded with the help of GeoNames. The IDs can best be researched using GeoNames Advanced Search. It is important to select the appropriate "Feature Class" here. As a rule (i. e. in towns and villages) it should be set to "city, village...".

All standard data must be specified as complete URL, i. e."", so that the web service can process it correctly.

An information sheet (download as PDF; currently only available in German) from correspSearch also informs about the search for IDs in standard files.

Step 4: Save CMIF file

You can save the CMIF file on your computer at any time in step 4. The file name is assigned from the title chosen in step 1 combined together with the current day and time.

You can edit the saved file at any time by loading an existing CMIF file instead of starting a new letter directory.

Step 5: Publishing and Registration

When you have finished compiling the letter index, you can save your CMIF file as XML. You must then make this XML file available online and register it with the web service correspSearch. To register, you only need to send us a short e-mail to with the URL of your CMIF file. Please do not hesitate to contact us if you have any questions or problems with the creation of your index of letters, the use of the CMIF Creator or the publication of your CMIF file!

Further questions?

For more information see the FAQ section.