7.11
The players, coaches or any member of an offensive team shall vacate any space (including both dugouts) needed by a fielder who is attempting to field a batted or thrown ball.
PENALTY: Interference shall be called and the batter or runner on whom the play is being made shall be declared out.
4.05
(a) The offensive team shall station two base coaches on the field during its term at bat, one near first base and one near third base.
( Base coaches shall be limited to two in number and shall (1) be in team uniform, and (2) remain within the coach’s box at all times.
PENALTY: The offending base coach shall be removed from the game, and shall leave the playing field.
Rule 4.05 Comment: It has been common practice for many years for some coaches to put one foot outside the coach’s box or stand astride or otherwise be slightly outside the coaching box lines. The coach shall not be considered out of the box unless the opposing manager complains, and then, the umpire shall strictly enforce the rule and require all coaches (on both teams) to remain in the coach’s box at all times.
It is also common practice for a coach who has a play at his base to leave the coach’s box to signal the player to slide, advance or return to a base. This may be allowed if the coach does not interfere with the play in any manner.