3-3 point enclosures
See 3-3 6-4 enclosure.
See 3-3 5-3 enclosure.
This enclosure almost always starts with the 4-4 point rather than the 3-3 point. It aims to secure the corner territory, and is typically used when Black has a framework and he wants to turn it into territory.
See 4-4 3-3 enclosure.
DrStraw: It should be noted that the purpose of the 3-3 point is to finish the corner in one move and so more often than not an enclosure would be inappropriate. More often you will see an approach by the opponent or a longer extension down the side.