The IETF uses a consensus-driven process for developing computer-communications standards in an open fashion. An important part of this consensus-driven process is the pervasive use of mailing lists for discussion. Notably, in a small number of cases, a participant has engaged in a "denial-of-service" attack to disrupt the consensus-driven process. Regrettably, as these bad faith attacks become more common, the IETF needs to establish a practice that reduces or eliminates these attacks. The process is outlined fully in RFC 3683, "A Practice for Revoking Posting Rights to IETF Mailing Lists".
A PR-action identifies one or more individuals, citing messages posted by those individuals to an IETF mailing list, that appear to be abusive of the consensus-driven process. If approved by the IESG, then those identified in the PR-action have their posting rights to the IETF mailing list removed, and maintainers of any IETF mailing list may, at their discretion, also remove posting rights to that IETF mailing list. Once in effect, a PR-action remains in force until explicitly nullified and should remain in force for at least one year.
Please note that a PR-action deals solely with posting rights. Consistent with the final paragraph of Section 3.2 of RFC 2418, no action may be taken to prevent individuals from receiving messages sent to a mailing list.