CTLFLG parameter

A comma-separated list of values which call for matches on different subsets of the supplied parameters:

ORNULL will result in DLN=x and (NAME=n and (DOB=d or DOB=null)) 

ORNULL,ORID will result in DLN=x OR (NAME=n and (DOB=d or DOB=null))

ORID will result in DLN=x OR (NAME=n and DOB=d)

ORID,FLTALL will result in (DLN=x  and DOB=d) OR (NAME=n and DOB=d)

ORID,FLTALL,ORNULL will result in (DLN=x  and (DOB=d or DOB=null)) OR (NAME=n and (DOB=d or DOB=null))