See Ringer Equivalence Number.

Ringer Equivalence Number. Measurement of the load on a telephone circuit; if overloaded, not all handsets on the circuit will ring.

Ringer Equivalence Number - a telephone line can normally supply upto 4 REN, where a standard telephone/answering machine etc would equal 1 REN.

Ringer Equivalency Number A number which represents the ringer loading effect on a line. A ringer equivalency number of 1 represents the loading effect of a single traditional telephone set ringing circuit. Most modern telephones probably will have a REN lower than 1. The total REN expresses the total loading effect of the equipment on the ringing current generator (FXS). The REN of a Digium FXS board is 5 (representing "extension," i.e., parallel-connected telephones). The actual number of devices on the line may be greater than the REN limit, if their respective individual RENs are less than 1. See also: FXO, FXS

In DOS, you can do 'ren *.txt *.bak'. Ren does the same sort of thing, but better. Each filename matching the source pattern is renamed using the destination pattern. There are checks to make sure files are not lost or overwritten.

Renames a file or files. (Also RENAME)

OldFileName NewFileName REName a file that stays in its current directory. EG: ren * _*. This prefixes all files with an underscdore.