SalsaBoston.com Message Board 
Posted by Michelle on August 09, 2006 at 16:29:24:
In Reply to: NY circular style? posted by Michelle on August 09, 2006 at 11:57:53:
Got my own answer courtesy of Dave Morgan. Who know there was so much to learn!?
The "slot" is an alternative for the "line of dance". (The term slot came from hustle because the slot moved as you danced. It refers to the line in front of the guy on the cross body lead. In the ballrooms dances where the slot does not move it's called the line of dance).
Slotted "on 1" is often called LA style. Circular on 1 is often called Rueda style or Cuban style. On 3 dancers are usually Haitian.