I'm often combing through SANS regulations for electrical and control systems and sometimes I end up off on a tangent into related regs that I'm really not familiar with and I come across some real gems. Some of them are quite bazaar, some just make me smile for one reason or another and some initially seem strange but kinda make sense when you think about them.

One I bumped into this evening whilst looking for regs for a bulk water carbonation system (don't ask) I came across this one;

SABS 0252-2 Copper pipes shall not be used to take the discharges from urinals only, or in connection with
grease interceptors.
Copper pipes may be used to take the discharge from urinals, provided that such flow is diluted by
discharges from other upstream sanitary fixtures.

I had no idea it was illegal to connect a urinal to a copper drain....but I do now.