Can I just point out that the conservation of strangeness is not in fact an independent conservation law, but can be viewed as a combination of the conservation of charge, isospin, and baryon number.
It is often expressed in terms of hypercharge Y, defined by:Y =S+B =2(Q-1) where S =Strangeness B =Baryon Number Q=Charge and I=Isospin.
Isospin and either hypercharge or strangeness are the quantum numbers often used to draw particle diagrams for the hadrons.
Charming.
Reg, you took the words right out of my mouth