Genuine home made theorizing. May be incorrect.

Cross body leads

Makes the dancers change places with each other. The follow does most of the movement, the "travel". During the movement the follow may turn traveling, the lead may turn in place.

Open breaks

Usually makes the dancers change places with each other, but can also be used to get some extra oomph into a double or more spin.

• Lead steps up side by side with follow: Changing of positions.
• Lead steps out of the way: cross body lead.
• Lead does not step up or out of the way: Follow spins multiple times. Or you just collide.

Basics with open holds

Turn follow, lead or both on the spot, no changing of positions in the slot.

Open Holds

Purpose: Allows you to choose between cross body lead, turns in place and open breaks. So basically everything except mambos. Also makes positions where lead and follow face in the same direction end in embraces. The only way of avoiding cuddling is a back to back copa but then, come to think of it, you are not facing in the same direction anyway. So my statement stands.

Closed Hold

Purpose: Good for conversation, allows you to do cross body leads and mambos.

Cross holds

Allows moves that end in open holds or copas or similar where lead and follow are facing in the same direction, for example side by side or one in front of the other. So, if you want you and your partner to face in the same direction after a move, but not cuddle her in an embrace, start with a cross hold position. It is always a bit of work to get out of a cuddle. Cross hold also give you half an extra turn compared to a non crossed two-handed open hold, when turning.

Hammer locks

Allows for one full extra turn when making a turn.The locked in arm can also be used to start a copa.

Cross hold hammer locks

Cross hold hammer locks can be used as hammer locks to give a full extra turn but also for facing in the same direction if unwinding and keeping hold of both hands.

Additionally a cross hold hammer lock lets you wrap the follow one extra half turn. This is done by making the follow make an outside turn from the cross hold hammer lock position, further into the lock. This can be followed by the lead moving to the front of follow while wrapping follow's remaining free arm into a hammer lock, and follow then ends up in a double cross hold hammer lock position. This in its turn may be followed by a waist/hip initiated free spin.

Copas

When the follow suddenly changes direction, as in U-turn or V-turn, at least I think this is the definition. Is usually done on 3. In some cases on 7 (the second copa in tic-tac copa for example).

Shims

Motions with the arms and hands that changes grip, so that otherwise incompatible moves can fit together.

• Throwing follow's arm up
  • If two handed grip: forget about that hand, we're doing one handed grip from now.
  • If one handed grip: Follow should offer lead other hand.
• Throwing follow's hand down in a circle movement - follow concludes the circle and reconnects from above
• Placing follow's hand on lead's body - keep it there until lead signals he wants follow to drop it into one of his hands.