(last updated 2012-09-23) Resource Identifier (RI) Scheme name: attachment Status: provisional Scheme syntax: attachment:// Scheme semantics: Attaching resources to MHTML pages Encoding considerations: Unknown, use with care. Applications/protocols that use this scheme name: Opera-specific Interoperability considerations: Unknown, use with care. May be unsuitable for open use on the public internet. Security considerations: Unknown, use with care. Contact: Registering party: Dave Thaler Scheme creator: Opera Software ASA Author/Change controller: Either the registering party or someone who is verified to represent the scheme creator. See previous answer. References: http://en.wikipedia.org/wiki/MHTML, http://en.wikipedia.org/wiki/Opera_(web_browser) (file created 2012-09-23)