I make my own reference books in Mobipocket, and I would like to do the same in Epub. Unfortunately, the needed tags don't exist yet in the Epub spec.
I'm going to get the ball rolling by listing the three details I've noticed about Mobipocket dictionaries (if I missed one please point it out):
1, an entry in an ebook's metada that indicates it's a dictionary (necessary?);
2, two more entries in the OPF that indicate the input and output languages;
3, the set of tags in the content that define the parts of a data entry (idx:entry, idx
rth, idx:key, idx:short, idx:gramgrp, idx:subentry, idx:string, idx:ext-subentry). You can find more about them
here.
I don't think all of the tags are necessary. Here is what I would like to propose as a starting point. Also, I'm going to be shameless and simply copy the function and attributes of the existing Mobipocket tags. I've changed some of the names so they are easier to understand.
So, what do you think?