Uhm I had to be all raw on you but the pure fae of considerable power is a must only of greater glamours, glamours itself has no musts so as long as you have a plausible reason to have it (fairy artifact, blessing of a fairy god mother, funny and potentially painful relationship with a high sidhe etc).
You're right - it's under the "Fairy Magic" section but there's no "must".
Not even in the preorder.
Which means I should check the book before I preach about the RAW.
Richard