Yes, there are loads of U21s registered who don't count towards the limit. Most are academy players who aren't in first team consideration but Gyabi for instance is also in that list. I wasn't including them in the numbers if quoted though as they don't affect the 25.
Leaving out Collyer having just loaned him would be ridiculous.
Oh you meant in terms of squad limit, I thought you meant matchday loans.
Erm, my guess would be now that Giles is fit deregister Matty Jacob.