2.2 Message Syntax
An RSS object can be created and modified by clients and servers. Except where noted below, this section defines constraints under which both clients and servers operate.
Clients operate on an RSS object by using the Message and Attachment Object Protocol, as specified in [MS-OXCMSG]. The manner in which a server operates on an RSS object is implementation-dependent, but the results of any such operations MUST be exposed to clients in a manner that is consistent with the RSS Object Protocol.
Unless otherwise specified in sections 2.2.1 and 2.2.2, an RSS object adheres to all property constraints, as specified in both [MS-OXPROPS] and [MS-OXCMSG]. An RSS object can also contain other properties, but these properties have no impact on the RSS Object Protocol.
The values of the properties specified in sections 2.2.1 and 2.2.2 are taken from the XML elements of the RSS feed or atom feed. For details about the XML formats of the RSS feed and the atom feed, see [RSS2.0] and [RFC4287], respectively.