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 RFC 2119. Sections 1.5 and 1.9 are also normative but cannot contain those terms. All other sections and examples in this specification are informative.