GT.M deviceparameters do not have predefined abbreviations. GT.M recognizes deviceparameters using a minimum recognizable prefix technique. Most deviceparameters can be represented by four leading characters, except ERASELINE, READSYNC all deviceparameters starting with WRITE, and Z* deviceparameters in a mnemonicspace (such as SOCKET). The four leading characters recognized do not include a leading NO for negation.

For compatibility with previous versions, GT.M may recognize certain deviceparameters by abbreviations shorter than the minimum. While it is convenient in Direct Mode to use shorter abbreviations, Sanchez Computer Associates may add additional deviceparameters, and therefore, recommends all programs use at least four characters. Because GT.M compiles the code, spelling out deviceparameters completely has no performance penalty, except when used with indirection or XECUTEd arguments.