The IETF IMAP extensions Working Group shall revise and publish
standards-track extensions to IMAP4 for performing the following
functions:

1. Sorting, threading, and viewing (to be dealt with by one or more 
   mechanisms)

2. Access Control Lists

3. Message-level annotations

Revising the base IMAP4rev1 specification is out of the scope of this
WG. However, this WG will ensure that whatever extensions it does
propose do not worsen any existing problems in the base specification
of IMAP, nor do they make any such problems harder to address in the
future.