I was reading through another topic on here and kept running across the term "sister gyms."  I need a little clarification.  Does this mean that two gyms use each other's athletes and/or coaches?  Does it mean they are in business together on paper?  Or does it mean they support each other at comps and the sisterhood stops there.

Can some of you please list sister gyms so that I'll have a clue about what the heck is going on when I see that gyms with different uniforms come alive for some but not for others?  Thanks! 

P.S.  I hope that every gym, especially small gyms, has a sister gym if they need one.