The Point-to-Point Protocol (PPP, RFC 1661) is a mature protocol with a
  large number of subprotocols, encapsulations and other extensions. The
  PPPEXT working group exists to provide a forum for asking clarifications
  about the existing specifications and to defend against enhancements
  of questionable value. The group is not expected to create new
  specifications, and if a need for such work comes up, a recharter is
  required. The group may, however, advance existing specifications
  to the next level in the standards track, if a need for that comes up.
  Similarly, the group may classify existing specifications as Historic
  where this is appropriate.