The 'example' media type is used for
examples. Any subtype following the media type syntax may be used in
those examples. No subtype can be registered with IANA. For more
information see [RFC4735].
Note: The occurrence of an 'example' media type as a media type outside
of examples, e.g. in a Content-Type header, is an error and should be
reported to the implementor.[RFC2045, RFC2046]
specifies that Content Types, Content Subtypes, Character Sets, Access
Types, and conversion values for MIME mail will be assigned and listed
by the IANA.