[TSC-public] Progress on ELF / user defined tags

Richard Smith rsmith at fhiso.org
Sun Oct 29 12:52:34 CDT 2017

On 28/10/17 19:47, Albert Emmerich wrote:
> 1. I do not know any program which cannot handle GEDCOM files with
> "unknown" tags. The most common reactions are to ignore, to wrap in
> NOTE, and/or to create a problem list for the import.

Thanks.  That's good to know.

> 2. I will discuss this with the Gedom-L group. I think we will propose
> to add some more tags to this group.

A submission of that sort from the GEDCOM-L group would be most welcome.

> I agree to your point with _UID. The Gedcom-L group has different
> solutions within the group, and we have not agreed for a common solution
> how to handle this. However most programs of the group use _UID.

Searching through my rough list on ideas for ELF, I see I've noted a 
second and arguably more serious concern with _UID.  Presumably its 
purpose is to provide a globally unique identifiers for records so that 
they can be identified and merged if they are exported and reimported, 
but I've never seen that stated definitively software vendors who uses 

If this supposed motivation is correct, it only works if there are 
agreed semantics on the ownership of UUIDs.  Suppose I send a copy of my 
work to another researcher.  Some time later I notice an error.  What I 
thought was one person was in fact two, so I delete some facts from the 
individual already in my tree and create a second individual with them. 
This may happen over a period of time if I realise there is an error 
some time before working out what exactly is wrong.  Perhaps the 
researcher I sent my work to reaches a similar conclusion but splits the 
record in the other way, so now I have UUIDs X and Y, while the other 
researcher has X and Z, however my X corresponds to his Z and his X to 
my Y.  We need to prevent this, and, so far as I know, there is no 
current understanding in place that does so.

Richard Smith,                       FHISO   <http://fhiso.org/>
FHISO Technical Co-Coordinator       One Community, One Standard

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