- (acronym) . Classless Inter-Domain Routing; normally an IP address notation such as 192.168.1.0/24 indicating a block of addresses. The number after the slash indicates how many bits are in the mask; bits to the ''right'' are not masked.
- (acronym) . Controlled Internal Drug Release; technology for the controlled release of a hormone or drug, for example as used to release progesterone in beef cattle.