These are all the parameter specifiers up to the first lambda list keyword; if there are no lambda list keywords, then all the specifiers are for required parameters. Each required parameter is specified by a parameter variable var. var is bound as a lexical variable unless it is declared special.
If there are n required parameters (n may be zero),
there must be at least n passed arguments, and the
required parameters are bound to the first n passed arguments;
see Error Checking in Function Calls.
The other parameters are then processed using any remaining arguments.