Sign Your Card. The whole point of a signature is not that it is a secret symbol known only to you, but that only you can accurately duplicate it on command. It is not that hard for anyone can see a copy of your signature from public records, from a canceled check, and of course, from the credit card receipts you must sign.
A National Stock Number (NSN), as it is known in the US, or a NATO Stock Number, is a 13-digit numeric code identifying all the standardized material items of supply as they have been recognized by all NATO countries including the US Department of Defense.
National Stock Number. The Federal Stock Number (FSN) was an 11-Digit Numeric Code developed by the US Department of Defense in 1949 to identify items in the Army-Navy Catalog System. In 1974, the FSN was replaced with the National Stock Number (NSN) by simply adding two digits to the 11-Digit Code in positions 5 and 6 to signify the country of origin of the Numeric Code.