This page will outline the steps to take to figure out who will referee when there is no referee and there are two A/Rs who are both affiliated with one of the two teams.

If a step yields an answer as to who the referee will be, then stop. Otherwise, proceed to the next step.
 
1.  Ideally, the two A/Rs should try to agree who should referee factoring experience, fitness, etc.
 
2.  If one A/R is at or above the correct badge level for the division level and the other A/R is not, then the higher badged A/R will referee the game.
 
3.  The A/R from the home team will referee the game.

4.  If both A/Rs are from the same team, then they will flip a coin.