OR will not work because it is a reserved word.
i.e. OR is an expression that is used to test if bit xx "OR" bit yy is equal to a certain state.
Usually a Subprogram name is limited to 4 characters after the letter "O" (oh).
Usually if you start of a subprogram name with a digit you must use only digits.
If you start with a Alpha character you should be able to use any combination of Letters or numbers after the first Letter.
As for why "OC516" does not work...? What alarm/Error comes up?