The Atom syndication format is a generic XML format for representing
collections. Profiles are one way how Atom feeds can indicate that
they support specific extensions. To make this support visible on
the media type level, this specification adds an optional "profile"
media type parameter to the Atom media type. This allows profiles to
become visible at the media type level, so that servers as well as
clients can indicate support for specific Atom profiles in
conversations, for example when communicating via HTTP. This
specification updates RFC 4287 by adding the "profile" media type
parameter to the application/atom+xml media type registration.