This seems to me the best place to ask such a question. If it’s not the appropriate board, let me know.
I have been working on porting an Inform 6 zcode game to TADS 3 (with the original author’s permission, of course), and is close to a beta release now. Before the release, however, I’d like to get the meta-information of my game ready, and that includes the IFID.
The original Inform 6 game has no IFID, I know from reading the Treaty of Babel that I can assign a legacy IFID for it. The question, though, is that what my TADS 3 game should use? Do I use the legacy “ZCODE-X-YYMMDD-XXXX” IFID from the Inform 6 game? Do I use a completely new one? Use both?
In section 2.2 of the Treaty, it says “If a game is ported from one system to another […], the port receives a new IFID.” I think that probably makes sense, because the releases are separate files in different formats and need different interpreters, so the TADS3 remake is, for the purposes of archiving, cataloguing and playing, different enough to warrant a new IFID (it’s not a bugfix release that’s intended to replace the previous version).
You could consider additionally providing the old IFID in the iFiction record, as per section 5.5.1, if you make sure that the TADS3 IFID comes first (because “In all cases of doubt, if a single IFID must be extracted, the first one occurring in the story file should be used.”).