[user104658]

Originally Posted by parmnion

Grown men playing at being cub scouts.

This. It's just a boy's club. One of my mum's best friends was a "grand master" and my wife's grandad was pretty "high up" too... There's no great mystery or secret organisation going on, it is exactly what it looks like. A working class protestant men's circlejerk.

They probably do pass each other work (which is nepotism and of questionable legality) / use it for making "trade buddies" e.g. Builders getting to know electricians and plumbers and then hiring them in on projects... Which is, I suppose, almost sensible in terms of wanting to ensure reliability (can't **** each other over because then they'd be "out of the club").

The nepotism is most likely what the secrecy is about. Other than that, it's basically just a sectarian protestant drinking club.