Entry points defined using the ENTRY statement can be accessed only after the main entry point (identified by Program-Id) has been called, unless the program is statically linked, or the MFENTMAP facility has been used.
A nested program cannot contain ENTRY statements.
An entry point is an alternative route into a program; an entry point is not treated as a separate program.
All program entry point names are truncated to 30 characters (so the first 30 characters of all entry point names must be unique).