Is grounding your putter on your line legal?

Answer 1

16-1. General

a. Touching Line of Putt

The line of putt must not be touched except:

(i) the player may remove loose impediments, provided he does not press anything down;

(ii) the player may place the club in front of the ball when addressing it, provided he does not press anything down;

(iii) in measuring - Rule 18-6;

(iv) in lifting the ball - Rule 16-1b;

(v) in pressing down a ball-marker;

(vi) in repairing old hole plugs or ball marks on the putting green - Rule 16-1c; and

(vii) in removing movable obstructions - Rule 24-1.

(Indicating line for putting on putting green - see Rule 8-2b.)