Some CMs have been sticklers about it, but I think that was because the changes in practice were new. From what we've seen, when it is obvious that the child in question is quite young or disabled, the CMs allow the parent to scan for him/her. But it can cause problems when one parent tries to scan for an entire group (and isn't ready and organized when it is time to scan), and slows down the whole ride line. This has happened a few times -- so frustrating.