Can flip, delete, shift, or return effects target covered cards?

Question

Accepted Answer

Only if the text says so. Unless its wording says 'covered' or 'all', an effect can choose only the uncovered card of a stack. 'All' reaches covered cards too, so an effect that flips all cards also flips covered ones. The rulebook says covered cards can only be affected by text that names them.

Compile: Main 1

Can flip, delete, shift, or return effects target covered cards?