Let's go to the videotape:
THROW-IN ADMINISTRATION 7-6-5: Teammates shall not occupy adjacent positions which are parallel
to and within 3 feet of the boundary line if an opponent desires one of the positions.
7.6.5 SITUATION: Prior to a throw-in on the end line near A’s basket, A1, A2
and A3 line up shoulder-to-shoulder parallel to the line and: (a) within 3 feet of it;
or (b) more than 3 feet from it. In both cases, Team B requests space between
the Team A players. RULING: In (a), the request is granted and a Team B player
may position between each of the Team A players. In (b), the request is denied.
Not to be confused with:
JUMP-BALL ADMINISTRATION 6-3-3: Teammates may not occupy adjacent positions around the center
restraining circle if an opponent indicates a desire for one of these positions before the referee is ready to toss the ball.