Looking at my mainsail recently I noticed that many slides on the sail are being held by a line on the lower section of the sail. Thinking this as jerry rigged, I purchased some extra slides and slide shackles. Took some time this weekend to review and perhaps replace when I realized it seems like this line with the slides in place is exactly how it should be. I have no experince with this set up. My immediate thoughts are that is helps to lay the sail flatter at the cunningham rings when the sail is reefed and flaked. I hope I've been able to explain the set up and can someone confirm my theory or tell me I've got it wrong and explain what its all for?