NORTH TEXAS RULE 

4.8 COMPETITIVE TEAM FORMATION RESTRICTION (11U) Teams forming for play in 11U age competition are restricted to having three (3) underage players on their rosters that are playing up. These players must be 9 years of age per Rule 4.1.2 to be signed. Players 9 years of age per Rule 4.1.2 may not play on teams older than 11U. There shall be no more than three (3) 10U players on any event/official/game day roster. *Any player turning 9 years of age by December 31 of the current soccer year, shall be considered a 10U player for the entire soccer year

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This is for 11U teams ONLY.  They are not permitted to be added to any competitive team older than 11U.

Based on North Texas rule 4.1.2, it is any player that reaches 9 years old by December 31st of the current soccer year that is eligible to be added to a 11U competitive team. 

It is also limited to  only 3 underage players per team 

10U players  should not be club passed or added as guest players to 12U and older competitive teams.   There is also no such thing as club passing from a recreational team

Please make any parent and coach that registers an underage player for the competitive team aware that that player is no longer permitted to play or guest play with a recreational or academy team now that they have joined a competitive team.

They are choosing to be recognized as a competitive only player once they sign a competitive registration form and register with that competitive team.