The trailer manufacturer cannot violate the intent of the federal certification label. Look on yours (LH forward external section of the trailer) to see what the manufacturer said they provided. If the did provide yours with a spare they were required to register all tires delivered to you at the time of sale. Sometimes a dealer will swap out tires. If that happened to you the registered tire will not match the spare you have in hand if it does not match the info on the tire placard.
USN - RET - PDRL
DOD - RET - Journeyman Aircraft Mechanic
SSA - RET