I've noticed in some one pocket matches that when one wants to take a foul they just tap the top of the cue ball with the tip of their cue. Is this OK in the game of one pocket, or is it a house rule, or something that is agreed upon prior to the match? I know it is OK to just barely touch the cue ball with the tip when taking a foul, but I'm talking about just tapping the top of the cue ball. BCA rules state that an intentional foul is OK as long as a legal stroke is used using the tip of the cue. Would like some clarification on this.