Parameterised Protocols

A parameterised protocol is the description for an IP with one or more unbound formal parameters. It therefore defines a family of protocols, each protocol specified by binding the parameters to actual values.
A small dashed rectangle is superimposed on the upper right-hand corner of the rectangle with rounded corners as when defining a nested protocol. The dashed rectangle contains a parameter list of formal parameters for the protocol.
Communicative act can be marked with an asterisk in the parameter specification, denoting different kinds of messages that can alternatively be sent in this context.