To indicate the range of reason codes that it issues, the PFS returns low and high values in the PFSI structure at the time the PFS initializes. High byte values for PFSs are normally assigned by the LFS. The following fields in the PFSI indicate the low and high values for the range of reason codes:

pfsi_complow char;   /* low value for the PFS reason code high byte */
pfsi_comphigh char;  /* high value for the PFS reason code high byte */

These fields should be set to zero if the PFS does not support the pfsctl_errortext command.