On Pathfinder we use a slide on the track. The slide is the same size that is used for the sail. I drilled a small hole in the slide and tapped it to receive a small bolt. This is mounted at the bottom of the track. (the track extends to the goose neck)

We have a reefing system similar to what is described by others. I refer to it as slab reefing. All the lines are led to the cockpit starboard side. A quick overview would be go to the starboard side of the cabin top (on starboard tack if possible), release the main halyard from the horn cleat and lower it to a pre marked location. On either side of the halyard a set lines led to a pair of cam cleats. The operation is quick and simple. Ease the main halyard, pull on the forward reef line, pull the aft reef line, reset the halyard if needed. I put in a reef on Pathfinder in less than thirty seconds and will shake it out just as quick.

A couple of key points about the system: Never leave the cockpit (security), all lines led to the starboard side (starboard tack right away if needed), all lines are single purchase, boom is held by rigid vang system. Prior to the rigid vang we had a topping lift led to the same area of the reef lines so the whole operation was done at one spot in the cockpit. Quick, easy, and often used.