Short acronyms may be all upper case. All other letters are lower case. An exception is for identifiers matching a foreign language. In particular, we use all lower case where appropriate for C.
ALI word which stands for Ada Library
Information and is by convention always written in upper-case when
used in entity names.
procedure Find_ALI_Files;
I, use J instead; I is too
easily confused with 1 in some fonts. Similarly don’t use the
variable O, which is too easily mistaken for the number 0.