do you mean cleat? not cringle
It the cleat is near the front of the boom, it is for the aft reefing line. You'll need another way of securing the reefing cringle on the luff of the sail. On my boat I have a "reefing horn" set in the main's tack fitting. the mainsail has a handy strap with a hoop on each end set through the reef cringle. This strap hooks to the reefing horn, then I tighten the clew down from the mast. The clew reef line fixes to the port side of the boom, runs up through the aft cringle then back down to a cheek block on the starboard side boom, then guided foward through a few eyestaps to the cleat. The main thing is to make sure the cheek block is positioned to pull the clew backwards and down to keep the main's foot taut.