Slitherine

Ok, so apparently (so I'm told) you can ignore the list 'minimums' in the ToN Army Book in certain situations.
Is this only in cases which are specifically mentioned in the lists OR is there some general rule in regards to the lists?
Cheers

See Terry's ton errata feed. An example is my list, imperial guard 1812. You pick either foot or cav as a type, you then ignore the mins for the other type