Had a 1st last night

[constable]

Originally Posted by HokiePaul

I usually say "pick a spot" rather than "hold your spots" as it is technically more correct. I'm saying this to give notice that I am ready to toss the ball and the jump ball restrictions are in place. After "picking a spot", any legal movement is permitted.

Regarding "Let it hit the rim" ... I almost never say anything, but if I feel like a reminder is needed, I simply say "Let it hit". "Let it hit the rim" in incorrect as the ball hitting the backboard would end the restrictions.

Regarding the original post ... I came up two possible reasons why this could be illegal.
1) Are they changing positions around the center restraining circle? [Anyone know of a case play/definition that explains clarified what "around the restraining circle means? Is it 3 feet as in the OP? I can't find it.]
2) Are they taking a position in an occupied space?

I use similar jargon. I officiate FIBA. Many of our players play both FED and FIBA rules so it is a good reminder for the crew as well as the players.