Dumb question about a Shimano reel

Does anyone know what this cap-headed pin on the spool is for?  This is my fourth or fifth casting reel, second Shimano casting reel, and I have never seen one of these. There's nothing about it in the manual, can't find anything about it online, I'm really stumped.

Can anyone enlighten me as to what this pin is for? I don't want to just use an arbor knot and cover it up without figuring this out.

Thanks!

Makes spooling it really easy, without it braid can slip when you try to spool it. Just tie a loop in the end of your line, loop it over the screw head and start cranking, just make sure to keep good tension on your braid as you spool it.

I thought it might have had something to do with braid being slippery, but since I wasn't sure I decided it was better ask and appear a fool than to stay silent and remain a fool!

Thanks, IH!

It's not just a braid thing.  That sort of design has been around for decades, long before braid hit the mainstream.

-Allen

True, mono is pretty slippery, too.

Looks like most likely got your answer; Its there just to keep the line from slipping on the reel. I wouldn't recommend tying braid directly to the spool anyway, I Always put a mono backing even if its a few yards. Also there are a few knots that help prevent slipping, which I'm sure you can find on knot wars.

Maybe I'm tying it wrong, but I've never had any confidence in arbor knots. They usually snap or slide on me while I'm trying to tighten them. I've also never been spooled by a fish I cared a whole lot about (bat rays don't count) so maybe it doesn't matter anyway....

I just tie to the spool with a uni knot.