Sets, by virtue of their nature, give rise to sets that don't have their  ature

Categories do the same 

In the human sphere, a protocol essentially boils down to a list of  things to be kept in mind

And so each gives rise to cousin protocols and cou ter protocols

There is no end to this, the engine of variety,  similarity and variation driven in an endless dance of novelty on a bed of boring regularity,  

Todays novelty becomes  tomorrows regularity, as sets accumulate sets , and strive to gobble all, and plug the perennial leakage