Tivoli Storage Manager allows macros to invoke other macros, for example, macro 'A' invokes macro 'B' which, in turn, invokes macro 'C'. This is nesting to 3 levels. The limit is 10 levels (the inital macro plus nine levels of calls within macros currently executng). There is no limit to the number of different macro calls that may be made within a macro as long as the calls are not nested.