PRO/5 has no special rules or requirements for naming disk files. PRO/5 will support any naming conventions used by the host operating systems. As a practical matter, you should avoid naming files in a manner that could cause problems when porting your software between operating systems For example, some systems keep file names in upper case only whereas some systems allow both upper and lower case. When designing application software you should consider the following guidelines for naming programs and data files.
NOTE: The following are suggestions (not requirements imposed by PRO/5) for disk file names. The name should:
Begin with a letter (A..Z).
Not be longer than 6 characters.
Not contain any characters other than A..Z and 0..9.
Avoid names that might have special meaning to a host system such as "CONSOLE" or "PRINTER".