Did get used but the preferred was LWE [long weekend ] cos thats what it said on the leave pass if you got one. Extended long weekend was Monday off aswell.
Used to be SWE as well but they eventually just put the station cards in the seperate boxes on the gangway for weekend leaves .
It was used during my time. Friday while Monday. I never heard the term Nozzer or Crab. It was Od, Brylcream boy or Erk. OD is a state of mind and lifestyle that I embraced with gusto and still live up to.