rbl
     realtime blackhole list internet, spam
     
     

rbl /r-b-l/ abbreviation: "realtime blackhole list". a service that
   allows people to blacklist sites for emitting spam, and makes the
   blacklist available in real time to electronic-mail transport programs
   that know how to use rbl so they can filter out mail from those sites.
   drastic and controversial but effective. there is an rbl home page
   http://maps.vix.com/rbl/usage.html.


see also:
spam