This ITU-T Recommendation | International Standard specifies: a) procedures for the transfer of data and control information from one presentation-entity to a peer presentation-entity; b) the means of selecting, by means of functional units, the procedures to be used by the presentationentities; c) the structure and encoding of the presentation-protocol-data-units used for the transfer of data and control information. The procedures are defined in terms of d) the interactions between peer presentation-entities through the exchange of presentation-protocol-dataunits; e) the interactions between a presentation-entity and the presentation-service-user in the same system through the exchange of presentation-service primitives; f) the interactions between a presentation-entity and the session-service-provider through the exchange of session-service primitives.