Change in tag MWG ids after 11.54 ?

[Mac2]

I've got a bug report than my software no longer displays certain data tags based on Composite tags after the user has switched to an ExifTool version larger than 11.54.
My software extracts metadata via ExifTool by using a complex args file and then ingesting the XML output ExifTool produces. This worked for many years.

I've run some tests with the 11.54 (good) and the 11.61 (no good) and I've identified the reason. In the XML output the tag ids used for MWG tags differ:

11.54
<MWG:City>
  <rdf:Description et:id='City' et:table='Composite'>

11.61
<MWG:City>
  <rdf:Description et:id='MWG::City' et:table='Composite'>

so the tag id has been prefixed with MWG:: for some probably good reason.

This breaks the code in my app which uses hash maps to lookup tags quickly, and also the metadata stoted in the database, which also uses the "original" MWG tag ids, without the MWG:: prefix added recently.
I need to think about the consequences for all databases in use and how to migrate them...

I did not find anything in the release notes about this change. What are the reasons to change the tag ids?

[Phil Harvey]

The et:id entries should be consistent with the output of the -listx option.  This is the only purpose for these entries (to allow the tags to be referenced in the -listx output).  I don't understand why this is causing a problem.

- Phil

[Phil Harvey]

I've posted my response to your other question in this thread.

- Phil