The use of "*-*" to denote a dummy zero field which may be filled in or overriden later (for example, the length in an executed MVC instruction) is a very widespread notation convention in mainframe assembler. It is used in examples in the HLASM Programmer's Guide, for example the following executed instruction in the TERM user exit example:
UPPERSTR OC OPENPARM(*-*),0(BUFREG) Move and uppercase string This is just part of the common notation used by assembler programmers, which should preferably be mentioned during assembler training courses. I do not think it needs explaining when used any more than it should be necessary to explain any other common convention, for example that R1 is a name with value 1 conventionally used to refer to general register 1. Jonathan Scott, HLASM IBM Hursley, UK
