In "Pleasure at Her Majesty's," a hillarious British comedy special to be seen on Channel 26 Sunday night at 11 o'clock, "others too numerous to mention" are in fact mentioned.And high time, too.

The special, just over an hour, was filmed at a London benefit last year which saw the reuniting of many of the stars from "Monty Python's Flying Circus" as well as members of the "Beyond the Fringe" troupe and other ace British loonies.

Though it was very poorly photographed, and though onstage shenanigans are annoyingly intercut with useless backstage footage, the program serves as a mad index to British humor, especially the bad-boy intellectual variety, of the late '60s and '70s.

The program opens with The Dead Parrot, a Python sketch now so classic that the audience goes into convusions at the first line: "I wish to register a complaint." The line is spoken by a man entering a pet shop to return a parrot whom he contends is "demised" and the owner insists is merely "pining for the fjords."

The night includes Peter Cook's monologue of a miner who wanted to be a judge but couldn't pass the rigorous exams, a courtroom scene in which a mass murderer tels the judge and lawyers, "I did the murders but as you're all so looking forward to this, I plead 'not quilty,'" and a final definitive essay on the proper care and throwing of the whipped cream pie.

The Public Broadcasting Service (PBS) acquired this film for its fund-raising "Festival '77," but did a disservice by not adding to it identifications of the players involved, leading to great but hardly defeating confusion. Instead, some PBS stations insisted on an edited version with a few harmless naughty words bleeped out. A spokesman for Channel 26 says the version televised here will be unbleeped.