Ask a ball to be marked if your are off the green ?

Val is correct. The relevant extract from the Rules:

15.3b(2) When Relief Is Allowed from Interfering Ball. If a player reasonably believes that another player’s ball anywhere on the course might interfere with the player’s own play:

The player may require the other player to mark the spot and lift the ball (see Rule 14.1), and the ball must not be cleaned (except when lifted from the putting green under Rule 13.1b) and must be replaced on its original spot (see Rule 14.2).

Penalty for Breach of Rule 15.3 General Penalty.

This penalty also applies if the player:

*Makes a stroke without waiting for a helping ball or ball-marker to be lifted or moved after becoming aware that another player (1) intended to lift or move it under this Rule or (2) had required someone else to do so, or

*Refuses to lift his or her ball or move his or her ball-marker when required to do so and a stroke is then made by the other player whose play might have been helped or interfered with.