Weird. Do you have a link to the list?
Hmm. The
Permitted/Prohibited Items link on the FAA website redirects to the TSA, and the
"other prohibited items" link on the TSA website redirects to the FAA
If I can find the letter I received (which has a list on it), then I will scan and post. However, if you do a search for relevant terms like "magnets" and "checked luggage", there are a few likely results. The first time I heard this, however, was when I called the EXP desk, told them what was missing, and after looking up a list they said that magnets were not permitted.
In the end, it's probably regulated by how energetic or ruthless the screeners are feeling at the particular moment when your bag is checked.