Hints about the choices in completing-read-multiple (in crm.el)

[Nordlöw]

I am currently building functions for searching, replacing and C/C++
refactorings. In these I have found the *efficiency* in using
completing-read-mutliple() of sets of gcc-functions/types/attributes,
file-types/groups really usable. I would however like to extend its
logic a bit so that the user can get a small explanation/documentation
about a specific choice in a pre-specificied multiple-value-doc-set.
Any tips?

Thanks in advance,
Nordlöw