How to Recognise a Mason is a sketch that appears in "The Buzz Aldrin Show," the seventeenth episode of Monty Python's Flying Circus.
Synopsis[]
A voiceover (Eric Idle) looks at the handshake between the city gent (Terry Jones) and Mr Leavey (Idle) in slow motion, and the actors perform the handshake again but slower. In response to the question 'what other ways are there of recognising a free mason?' it cuts to five city gents hopping along a busy street with their trousers at their ankles. Two masons (Jones and John Cleese) with one trouser leg rolled up greet each other by shaking hands through each other's legs. Another mason (Graham Chapman) half naked wearing fake antlers and sash saying 'I'M A MASON' stands at a bus stop.
Another voiceover (Cleese) explains you must isolate a mason from the general public once identified, and then it is possible to cure him from Masonic tendencies through behavioural psychotherapy.
It cuts to a billboard with 'AN APOLOGY' printed on it. A group of Gumbys walk on screen and in unison introduce the next item, "Insurance Sketch'. When it doesn't cut to it, they repeat louder.