"level 2 flag" ?s

first off, i call the flags that you place over secret combos level 2 flags because they aren't set right away until they are activated by a secret flag in the first place; my first question is What should we refer to these flags as so everybody knows what i'm talking about? secondly, & more importantly, what flags, when placed over a secret combo, do not function as a "level 2 flag"? like an example that i do know of, is placing an enemy placement over secret flag 16, it does nothing; what other cominations of level 2 flags can you think of that have no purpose/do nothing?