MSEC function modifies a
MACRO, setting its secure flag to
true. Some functions behave differently in the presence of secure macros, namely:
SNAPSHOTof a secure macro does not produce the actual code of the macro but a comment indicating the macro is secure.
DEREFcannot operate on secure macros.
Making a macro secure is handy when returning a macro as the result of another macro call. The returned macro cannot be altered or inspected by the calling code thus providing a level of security and enabling the return of a singleton macro.