(RFC 5228 published January 2008, subtype last updated January 2008)

MIME media type name: application
MIME subtype name: sieve
Required parameters: none
Optional parameters: none
Encoding considerations: Most Sieve scripts will be textual,
   written in UTF-8.  When non-7bit characters are used,
   quoted-printable is appropriate for transport systems
   that require 7bit encoding.
Security considerations: Discussed in section 10 of this RFC.
Interoperability considerations: Discussed in section 2.10.5
   of this RFC.
Published specification: this RFC.
Applications that use this media type: sieve-enabled mail
  servers and clients
Additional information:
  Magic number(s):
  File extension(s): .siv .sieve
  Macintosh File Type Code(s):
Person & email address to contact for further information:
   See the discussion list at ietf-mta-filters&imc.org.
Intended usage:
   COMMON
Author/Change controller:
   The SIEVE WG, delegated by the IESG.