When an On-Ice Official is yelling "Play the ring" or "Sticks down" it is usually because there is an infraction occurring that is illegal, but has not yet caused a material change in advantage - and therefore there is no penalty to be called yet. (see The First Principle of Officiating).

Often this is due to using your body or stick to interfere on a play, or due to over enthusiastic checking that is getting too high - up near the hands, etc.

When you hear an Official calling these phrases out, consider what you're doing and pull back if you think you're at fault. If a material change of advantage does occur - you're likely to get a penalty.