Identifiers (GNAT Coding Style A Guide for GNAT Developers)

### 2.2 Identifiers ¶

- Identifiers will start with an upper case letter, and each letter following an underscore will be upper case.

  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.

- Use underscores to separate words in an identifier.
- Try to limit your use of abbreviations in identifiers. It is ok to make a few abbreviations, explain what they mean, and then use them frequently, but don’t use lots of obscure abbreviations. An example is the `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;

- Don’t use the variable name `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`.