Initialism of Royal Engineers, a regiment in the British Army.

(computing theory) Abbreviation of "recursively enumerable"; the class of decision problems for which a 'yes' answer can be verified by a Turing machine in a finite amount of time.

(Egyptian mythology) Alternative form of Ra

About, regarding, with reference to; especially in letters, documents and emails.

(music) a syllable used in solfège to represent the second note of a major scale.

again, anew / a completive or intensification of the base; up, a-, out / back, backward

Regarding, re.

rupee

(in company names) Reinsurance.

A municipality of Vestfold, Norway