Originally Posted by Bump
Toe rails are used to keep you in the boat. The holes are for drainage and should not bear any strain or pull.
Maybe for teak toe rails, but not true at all for perforated aluminum toe rails that the OP was talking about. These became common in the early days of the IOR rule. Like others have said, they are/were actively used to attach spinnaker sheet and guy turning blocks, barber hauler snatch blocks, a boom preventer, etc... No, you can't lift a boat using them, but there's very little you can do that will do any more than maybe make a ding that turns into a nasty meat hook. If used to attach a preventer, the boom will break long before anything happens to the toe rail. Used to do this all the time on an IOR mini-maxi. The only problem with them is if you have crew hiking, you need to use some foam pipe covering to keep everyone's legs attached to their body.