M collates all canonic numeric subscripts ahead of all string subscripts, including strings such as those with leading zeros that represent non-canonic numbers. Numeric subscripts collate from negative to positive in value order. String subscripts collate in ASCII sequence. In addition, GT.M allows the empty string subscript in most contexts, (the null, or empty, string collates ahead of all canonic numeric subscripts).

GT.M allows definition of alternative collation sequences. For complete information on enabling this functionality, refer to the "Internationalization" chapter in this manual.