A universal identifier is a string of up to 11 alphanumeric characters of which the first letter is in the range A to L. A universal identifier may be defined at any point in the program after #CORE and must be unique.
However, the exception to this are universals whose names begin with D and L, these cannot be defined as the compiler will itself assign values to such identifiers as follows:
Links to universal identifiers starting with: A B C E F G H I J K