output from /usr/lib/cups/backend/snmp

when debug printing service using cups-snmp (8), how to understand 4th field return by snmp query ?

i.e.

/usr/lib/cups/backend/snmp 8.8.8.8 

gives

printername socket://8.8.8.8 "local printer name" "model name" "3th field" "4th field"  

where

  • most of the time local name and model are same (e.g. "FS-3820N" ), (I guess no one bothered to set a normalized name for printer)
  • "3th field" is a descritpion of printer (e.g. “MFG:Hewlett-Packard;CMD:PJL,PCLXL,PCL,PDF,POSTSCRIPT;CID:HPLJPDLV1;1284.4DL:4d,4e,1;MDL:HP LaserJet 600 M601;CLS:PRINTER;DES:HP LaserJet 600 M601; )
  • 3th field can be empty

  • "4th field" is mostly empty, but sometime set, it look like a user field.

I was unable to find a proper description of /usr/lib/cups/backend/snmp ‘s output however.

  • Anyone ever use this command ?
  • if so, what is the signification of 4th field ?

(sles 12sp3 if reveleant)