Definition of "Tets"

A good pint of Tetleys pulled through the auto vac system, which meant pulling three or four pints to create a single pint, was second to none. Outside Yorkshire, and going south, this system was used infrequently and, consequently, a pint of Tets served elsewhere would be very ordinary.

1990 October 6, Osman, “Re: The North - South Divide”, in free.uk.pubs‎ (Usenet)