List numbering with letters

Question

Suppose i need to number list in French text like the following in English:

a)
b)
c)
d)

I know that in Ukrainian it is common to omit ґ because we also have г. Sometime letters з, о, and ч also not used because they are similar to 3, 0, and 4. Which letters should be used and which should be omitted in French?

I would like to accept an answer which refers to some rule provided by an institution which takes care about French language or some secondary source which is based on this rule.

Answer 1

No letters should be omitted. You can use from a to z and from A to Z.

Only diacritics are omitted: à, â, ä, é, è, ê, ë, …, ç, œ, æ.

Official reference : Lexique des règles typographiques en usage à l'Imprimerie nationale (Unfortunately, this work isn't available online.)