All language tags should be named according to established standards. E.g. german = de (not current <ge>) spanish = es (not current <sp>) Check others
Check that poitevin tag does not conflict with existing standards of modern languages.
Determine the tags in use, determine the ISO standard, and then change from old to new
@ps2270 @thuchacz , @Pantagrueliste, @TillmannTaape - FYI (but Terry will take care of this and update schema appropriately)