Laws of Cricket 1980 Code - Law 15
1. Call of Play
At the start of each innings and of each day's play and on the resumption of play after any interval or interruption the umpire at the bowlers' end shall call "play".
2. Practice on the Field
At no time on any day of the match shall there be any bowling or batting practice on the pitch.
No practice may take place on the field if, in the opinion of the umpires, it could result in a waste of time.
3. Trial Run-Up
No Bowler shall have a trial run-up after "play" has been called in any session of play, except at the fall of a wicket when an umpire may allow such a trial run-up if he is satisfied that it will not cause any waste of time.
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