Yeah, those aren't telltales. They're reefing lines. On a modern Marconi/Bermuda rig, we rely on tack and clew reef points to hold the sail down, and the reefing lines or nettles along the midsection of the sail are just to gather the excess. But on a sail like this, or an old gaffer, they have many more reefing lines, which are all tied to the boom or in this case the foot of the sail. There are many to distribute the force, so they wouldn't tear out like if we used 3 nettles to try and hold the midsection of the sail down. Wow, 5 reef points!