The name and parameter properties of a behavioral feature, such as an operation or signal. A signature may include optional return types (for operations, not for signals).
The signature of an operation is part of its declaration. Some (but not all) of the signature is used for matching operations and methods to check for conflict or overriding. The details of what is included for matching and what is excluded may be language specific. If two signatures match but the remaining properties are inconsistent (for example, an in parameter corresponds to an out parameter), then the declarations conflict and the model is ill formed.