Annex 1  Checksum for error detection and status information
 1     Introduction
 2     Location of checkwords, flags, identification number, and included samples
        2.1     Location of checkwords, flags and identification number
        2.2    Samples included in checkword calculations
 3     Definitions of data words
        3.1     Checkword values
        3.2     Ancillary data housekeeping, checkwords and flags
        3.3     Error flags
                  3.3.1     Definition of individual error status flags
                  3.3.2     Degrees of implementation