USGA Rule 10.2b suggests that your caddy should not stand behind you along the line of putt when making the stroke. However, the USGA and R&A did some exceptions to this rule.  For example, a caddy may stand behind a golfer holding a sunshade or umbrella until the time to hit the shot. The R&A and USGA allowed these exceptions as long as the golfer is not using the situation to his advantage.