AMSU-A Quality Control Questions

I am unsure what the AMSU-A QC flags mean in the qcmod_f90 file.

Specifically this two topics:

!  Reject because sval > limit in subroutine qc_amsua over open water          
  integer(i_kind),parameter:: ifail_sval_qc=52                         
!  Reject because factch5 > limit in subroutine qc_amsua over open water      
  integer(i_kind),parameter:: ifail_factch5_qc=53   

Could someone help me with this clarification?

Regards

César Magno.