This, combined with V.28 is the CCITT standard equivalent to EIA's RS-232C standard.

ITU-T rec. listing definitions for interchange circuits between terminal equipment (DTE) and data circuit-terminating equipment (DCE). Vertical, Volts, Velocity

ITU-T Recommendation specifying the interchange circuits for interfaces between DTE and DCE. http://www.itu.int/rec/recommendation.asp?type=folders&lang=e&parent=T-REC-V.24

An International Telecommunication Union specification defining interchange circuits between data terminal and data communications equipment (for example, between a PC and a modem). V.24 is equivalent to the RS-232 specification (see RS-232).

Circuit defs between DTE and data circuit terminating equipment.

ITU-T Rec. V.24 listing definitions for interchange circuits between terminal equipment (DTE) and data circuit-terminating equipment (DCE).

Definitions of interchange circuits between DTE and DCE.

The 24th CCITT recommendation in the V series, listing the definitions for interchange circuits between a DTE and a DCE.

A CCITT interface recommendation defining interchange circuits; similar to and compatible with RS-232.

ITU-T standard for a physical layer interface between DTE and DCE. V.24 is essentially the same as the EIA/TIA-232 standard. See also EIA/TIA-232.