The Public Folder–Based Free/Busy Protocol is used to publish information that describes the availability of a user or resource. This protocol extends the Message and Attachment Object Protocol, which is described in [MS-OXCMSG].
Sections 1.8, 2, and 3 of this specification are normative and can contain the terms MAY, SHOULD, MUST, MUST NOT, and SHOULD NOT as defined in [RFC2119]. Sections 1.5 and 1.9 are also normative but does not contain those terms. All other sections and examples in this specification are informative.