a SIRI Service Participant is a participating system that exchanges SIRI messages with another Service Participant

NOTE Each Service Participant has a unique identifier, (the Participant Code), which provides a scope (i.e. unique namespace) for all non-global data references, such as stop identifiers, vehicle identifiers, and also for message identifiers of requests and subscriptions. Service Participants will either be SIRI Functional Service systems providing information, or accredited client systems that send request and subscriptions to the services to obtain information.