RPG II Question

[Jerry Adams <jerry@xxxxxxxxxxxxxxx>]

I really don't expect an answer.  In fact most people will probably just 
delete this when they see the subject line.  But this is puzzling the 
heck out of me.

I went in to an RPG II program (old package) to do some simple 
maintenance changes.  I noticed that one of the files was defined as:

FFilenameIPEAFBlenRlenLK1AIOvKlocEDevice+
FLISTCONSIF         27  1AI     1 DISK  

Well, the key length is '1' but the key actually starts in position '2' 
of the record.  The purpose of the file is to validate a code entered on 
a panel:

C           WRCONS    CHAINLISTCONS             54
C   54                SETON                     99
C   54      *ZEROS    ADD  23        $            
C   54                GOTO X2A                    

The first position of LISTCONS is a status byte.  Currently every record 
has an 'A' in position 1.  The program has been successfully validating 
these codes for years.  How is that possible?  I even put the program 
under debug (ISDB) and verified the codes entered (WRCONS) and in the 
file (ABCONS) are the same after the chain, and that indicator 54 is 
turned *Off.

It has been awhile since I programmed on a S/36, but I'm pretty sure 
that, first, when the program started up it would give me a file 
mismatch error.  Is the i5 really smart enough to say, "Well, he botched 
that.  Let's just use what is really in the file."?

Thanks.