Some formats were already documented, and I maintain links here:
the mares nemo link is dead. do you have a local copy?
I intend to cleanup and publish my internal notes on the libdivecomputer website some day, but at the moment I simply don't have the time for it. Anyway, the result should be something like this page I made for the Uemis:
maybe it would be nice to add that tho the repo as documentation?