prototype

An optional part of a "subroutine" declaration telling the Perl compiler how many and what flavor of arguments may be passed as "actual arguments", so that you can write subroutine calls that parse much like built-in functions. (Or don't parse, as the case may be.)

A pre-production, functioning specimen(s) that is the first of its type, typically used for the evaluation of design, performance, and/or production potential. 2. A model suitable for evaluation of design, performance, and production potential. [JP 1-02]