I think you'll find that any shipping process that could put the package on an airplane technically prohibits matches. However, it is not enforced. eBay match purchases are shipped USPS routinely via first class or Priority.

To my knowledge, there are no nitrates in book matches that would be sensed by the airline security checks. They will find them only in a hand search.

The reason to allow them in hand luggage but not in checked luggage is the fear that a baggage fire could erupt and be hard to detect and to put out in the crowded hold. There's a limited amount of damage to be done in the passenger cabin with matches. Most all seats and accessories are fireproof today. I guess you could set the airline magazine on fire [g].