raw mode = R = rc file

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://www.spam-rbl.com/>.

--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.