GEDCOM/ UserDef-Tag

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This page is an English extract of the German page GEDCOM/_Nutzerdef-Tag [1], for full details see the German page.

Name and Meaning




User_defined tag


User-defined tags may be used only to transfer information by GEDCOM files that can not be represented by the tags and structures explicitly described according to standard GEDCOM 5.5.1. The standard strongly recommends that priority being given to described tags and structures by the standard for the representation of information and to avoid the use of user-defined identifier as possible.

Formal Description of Permissible Values

Base: GEDCOM Standard Draft 5.5.1

According to the standard all user-defined tags that have not been defined in the GEDCOM standard, must begin with an underscore character "_" (0x95), and is defined as follows:

NEW_TAG"":= {Size=1:15}

A user-defined tag that is contained in the GEDCOM current transmission. This tag must begin with an underscore (_) and should only be interpreted in the context of the sending system. Systems that read user-defined tags must consider that they have meaning only with respect to a system contained in the HEAD.SOUR context

Agreements for _XXXX

The agreements for "user-defined" tags _XXXX are derived from the discussion on the Gedcom-L. They were decided by a vote of the program authors of the list.

N1 Use of User-defined Tags

For the overall implementation of the requirements of the standards for user-defined tags it is agreed, the explicitly in the GEDCOM 5.5.1 Standard described tags and structures will be primary used and the use of user-defined tags will be restricted for such events and facts, which can't be described by them.

N2 Name of User-defined Tags

User-defined tags must begin with an underscore "_". For the length of the names of these tags, the provisions of the standard apply, in particular to the first 15 characters of the name describe the indicator uniquely.

N3 Classification of User-defined Tags in the Overall Structure

There are no restrictions on the level, where the user-defined tags may be used. The requirement that the level number of the GEDCOM line may be not more than 1 higher as the level number of the previous line is to be met in all cases. It is particularly allowed to create at the level 0 ( records ) user-defined tags.

There is no restriction, which tags may be subordinated to a user-defined tag. In particular, it is permissible to subordinate to a user defined tag further user-defined tags.

N4 Explicitly defined Tags Subordinated to User-defined Tags

It is agreed that explicitly defined tags in the standard may be used as subordinated tags to user-defined tags. In this case all provisions of the standards apply for the subordinated tag with the exception of the in the Standard not listed assignment to this superior tag.

N5 Description of User-defined Tags

It is recommended to explain user-defined identifier used in a GEDCOM file in the file header. For this purpose, an approach based on the GEDCOM 5.3 draft is agreed:

a) The explanation of the user-defined tags used will take place in the header of the GEDCOM file and is initiated at level 1 ( i.e. directly to the record associated 0 HEAD ) by the tag _SCHEMA {0:1}.

b) Subordinated to _SCHEMA follows first the description of the context {1:M}, in which the user-defined tag is used. As much as necessary higher levels can be used for the description of the context.

c) Below of this context the to be explained user-defined tag follows {1:1}.

d) Below of the user-defined tag to be explained follows the explanation initiated with _DEFN. The definition should be written in English.


4 _DEFN Creation DATE of INDI record
4 _DEFN Godparent
5 _DEFN Rufname
3 _UID
4 _DEFN Unique identification of record
4 _DEFN Common family NAME after marriage

Examples of User-defined Tags

In agreements for the implementation of the GEDCOM standard 5.5.1 the program authors have already defined for instance following user defined tags:

_RUFNAME - See details as part of the tag NAME at section Agreement for "Rufnamen".

_LOC - Location record - See details as part of the tag PLAC at section Location Records and also in the GEDCOM 5.5 EL specification.

Overview of Known Users-defined Tags

The overview is created to represent the discussed and known user-defined tags by Gedcom-L ( also from third-party programs ). For program authors it is recommended to use, if applicable, the following list instead of re-inventing new user-defined tag.

In the second column a classification for the user-defined identifier is included. It means:

  • + the use of this tag was explicitly recommended in the agreements of the Gedcom-L group.
  • 0 this tags wasn't discussed in the Gedcom-L group.
  • - this tag shouldn't be used ( usually because the content can be exported to other agreed rules ).

In the last column the programs are indicated. It means:

  • AF2000 = Ahnenforscher 2000
  • AQ = Ancestral Quest
  • BKW = Brother's Keeper (Windows)
  • FO = Family Origins
  • FTB = MyHeritage Family Tree Builder
  • FTM = Family Tree Maker (DOS)
  • FTW = Family Tree Maker (Windows)
  • Gen = Generations
  • Leg = Legacy
  • PAF = Personal Ancestral File
  • Reu = Reunion for the MAC
  • TMG = The Master Genealogist

For the listing switch to the German page "GEDCOM/_Nutzerdef-Tag" [2].

Overview of Known None-standard Tags w/o underscore "_"

The GEDCOM standard permits the use of user-defined tags, but they have to start with an underscore. There are programs that do not meet these requirements and there are also GEDCOM files from older versions with tags, which are no longer valid. The following table provides an overview of such deviations from the requirements of the standard.

For the listing switch to the German page "GEDCOM/_Nutzerdef-Tag" [3]. This table is mainly based on "GEDCOM tags -".

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