klassenjm
commented
4 years ago Hi @RobH123: Mat is the abbreviation used in some English GNT texts, so I'm not sure how it is ambiguous. There are various cases where the 3 letter book code in \id is the same as the English \toc3 abbreviation. As you suggested though, I've added an additional language example (Spanish). The docs will be updated shortly.
https://ubsicap.github.io/usfm/identification/index.html#toc
As I understand it (and I could be quite wrong), the \toc3 field is intended to contain the local language abbreviation of the bookname as would be used in \r section references and \x cross-references. It might reasonably be in the range of 2-6 characters long.
If that's correct, the "Mat" example in http://ubsicap.github.io/usfm/master/identification/index.html is a bit misleading/ambiguous, because other than case, it also matches the MAT bookcode. Perhaps an example that showed a different abbreviation would help clarify, esp. a non-3-letter one like "Jd" or "3Jhn" or a non-English example.