The TSA website gives a list of permitted items for the carry-on. However, they also mention that the final decision lies in the hand of the security agents. Is it possible to ask the TSA to "pre-approve" my item for carry-on luggage, before I check in for my flight (e.g., a few days before my flight)?
By "pre-approve" my item, I mean having my item pre-inspected prior to a flight and then brought onto the plane without further inspection (or at least not getting refused because the security changed their mind).