"R" in the numeric designation signifies that the 1995 standard was reaffirmed (recertified) as an American National Standard in 2005 & 2011. No changes can be made to a standard during reaffirmation.
This standard describes requirements for the unique identification of fuel assemblies utilized in nuclear power plants. It defines the characters and proposed sequence to be used in assigning identification to fuel assemblies. This standard was developed primarily for commercial light-water reactor fuel, but may be used for any reactor fuel contained in discrete fuel assemblies that can be identified with a serial number as specified by this standard.