R passes to U1 or U2

[Texas Aggie]

We are assigned R/U1/U2 for varsity games, and the R has the responsibility to contact partners before the game and coordinate arrival time and such. The R also is responsible for the pregame, but there isn't anything that prevents him or her from delegating that responsibility, in whole or in part. The R can designate a tosser, and can designate another R for one or both games if there are 2. Typically, the assigned R will be the R for the second of 2 games or the one game.

[BillyMac]

Here are the 2007-08 IAABO, not NFHS, mechanics changes:

Added a signal (spreading of the arms) for when a defender is not in a closely-guarding position.
Referee can delegate jump ball toss.
Ball allowed on floor during time-out or intermission.
Boundary line coverage by trail farther sideline above free throw line extended.
Trail may rotate toward farther sideline, leads primary coverage area rotates.

There's also an exception to the "boxing in principle (official-ball-official)", but we're not using this here in Connecticut.