As LanX suggests the ; separates mandatory arguments from optional arguments. The * is pretty much a "match any argument type". The probable intent of the prototype is to ensure that the sub is normally called with at least one argument and may be called with somewhat over 80 arguments.

That looks pretty nasty to my eye. I'd be inclined to get rid of the prototype and add a runtime check that does a decent job of validating the arguments. Along with a decent set of unit tests that would provide easier to understand code, better documentation (the unit tests show expected usage for the sub) and much better regression testing over the long haul.