circled points

[Ravager]

when i use some models that are already made, in bone mode some of the bones have points that are circled. what do they mean or do? and how can i do the same with my bones in my models?

 

thanks

[luckbat]

See: Control Point Weights

[Ravager]

thanks that worked, but how do you select single CP points to add them onto the bone instead of just selecting compute CP weights all the time?