This document is a specification for the Background Intelligent Transfer Service (BITS) Peer-Caching: Content Retrieval Protocol. This is one protocol in a family of protocols that implement a distributed URL cache that is known as BITS peer-caching. Other protocols in the family are used to discover potential peers and to authenticate them. A client uses the BITS Peer-Caching: Content Retrieval Protocol to search an existing set of peers for content and to download from those peers.
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.