I'd like to create a glossary out of a collection with groups of entries starting by the letter A, B, C.... and a heading with the letter before the list of entries. If no entry starts with B, then I don't care about outputting "B". I tried with collection:previous/next but couldn't get it to work out of date and manual ordering (since I'd like alphabetical order). Of course, one can create another collection with each letter as en entry, but that seems tedious and not really clean.

Has anyone got an idea?