We use recutils for the GNUnet and GNU Taler names and numbers registry: https://gana.gnunet.org Using the recsel and recfmt tools that come with it you can autogenerate header/source files of constants from such a format into whatever language you need. For example, we do that for the GNU Name System record types: https://datatracker.ietf.org/doc/draft-schanzen-gns/ https://git.gnunet.org/gana.git/tree/gnu-name-system-record-...

So, quite useful if you have a protocol specification with constants from which you want to generate code.