Checkpoints: Protocol

The protocol class name is unique.
The protocol is used in at least one collaboration.
The protocol's brief description captures the purpose of the protocol and briefly summarizes the role it plays in the system.
The protocol represents a single set of cohesive responsibilities.
The signals in the protocol are all directly related to fulfilling the protocol's role in the system, and are not simply the signals used to communicate between two capsules.
The signals have been chosen in the most general way possible while still retaining clarity (e.g. in the case where several 'Out' signals all require acknowledgement, a single 'Ack' signal has been used as the response).
The protocol reflects a singular purpose in the system; where a protocol has a mixture of concerns (e.g. call processing and administration signals), it has been divided into several independent protocol classes.
Protocols have been defined in terms of what the use wants or needs to know instead of what the provider knows.
The guideline which determine the "side" of the interface to be conjugated is applied consistently. Asymmetric protocols are defined from the client (user) perspective to reduce the need to conjugate interfaces.
Asymmetric protocol classes are named to clearly indicate their directionality (e.g. 'ClientResourceInterface').