Rolex watches are assigned a country code of 3 digits as to where they are originally sold.
This code can be found stamped into guarantee certificates or printed on later ones and should help you determine if the certificate or guarantee card really goes with the watch. There are no country codes on certificates for the USA and codes are rarerly seen on certificates from the 1970’s and older.
The table below is a work in progress so please feel free to advise of any others you are aware of.