We've had it repeated ad nauseum who MAY NOT change crystals, but never who CAN. What qualifications are NOT required to do it are plainly stated, but never what credentials ARE required. AMA says only the manufacturer is qualified. Maybe that will change if Tony Stilman gets elected to AMA office.
Notice S Kaluf's comment in #2 "Thanks for passing the FCC's response along. It's nice to see them actually respond with the correct information for a change too. "
It's like that other bureaucracy, IRS. If you contact them for interpretation of a provision in the tax code that appears to have been written by some recent immigrant whose native language is Swahili, your odds of getting a correct answer are about 50/50.
Ergo, pick the answer you want and keep asking until they reply with that one.

Abel