The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY" and "OPTIONAL" in this document are to be interpreted as described in IETF RFC 2119. (http://www.ietf.org/rfc/rfc2119.txt
Terminology: sender and receiver. For simplicity in this document, where needed for general cases, the word sender is used to collectively refer to servers, producers and stores, and the word receiver is used to collectively refer to clients, consumers, and customers. The specific terms (server, producer, etc.) are defined in the context of the protocols in which they are used in the ETP Specification.
Protocol abbreviations. Each ETP protocol has both a name and protocol number as defined in the ETP Specification. For example the Core protocol is also Protocol 0. In some cases, this document may further abbreviate protocols, for example, Protocol 0 may be P0.