The input and output values may contain <NUL> (hex code 00) characters.

The collation transformation routine may concatenate a sentinel, such as <NUL>, followed by the original subscript on the end of the transformed key. This permits the inverse transformation routine to simply retrieve the original subscript rather than calculating its value based on the transformed key.

If you prefer not to append the entire original subscript, GT.M allows you to concatenate a sentinel plus a predefined code so the original subscript can be easily retrieved by the inverse transformation routine, but still assures a reformatted key that is unique.