In declarations, all EQUEL keywords are reserved. Therefore, you cannot declare types or variables with the same name as those keywords. Also, when you use the following EQUEL/Fortran keywords in declarations, they are reserved by the preprocessor and you cannot use them elsewhere, except in quoted string constants:

The EQUEL preprocessor does not distinguish between uppercase and lowercase in keywords. When it generates Fortran code, it converts any uppercase letters in keywords to lowercase. This rule is true only for keywords. The preprocessor does distinguish between case in program-defined types and variable names.

Variable and type names must be legal Fortran identifiers that begin with an alphabetic character.