DNS Opcode-8 (Refresh)?

[Barry Finkel]

I have a sniffer trace of dialog between some Win2k boxes and a Unix
BIND server.  There are some DNS records with 

     OPCODE=8

The sniffer decodes this opcode as "refresh".  I have been unable to
locate the RFC where this opcode is defined.  Can anyone point me to
the proper RFC?  Thanks.
----------------------------------------------------------------------
Barry S. Finkel
Electronics and Computing Technologies Division
Argonne National Laboratory          Phone:    +1 (630) 252-7277
9700 South Cass Avenue               Facsimile:+1 (630) 252-9689
Building 221, Room B236              Internet: BSFinkel at anl.gov
Argonne, IL   60439-4844             IBMMAIL:  I1004994