Editing Telephone jack and plug (section)

==Wiring==
[[File:Phone Cable.jpg|thumb|Typical U.S. modular phone connector]]
A standard specifies both a physical connector and how it is wired. Sometimes the same connector is used by different countries but wired in different ways.

For example, telephone cables in the [[United Kingdom|UK]] typically have a [[BS 6312]] (UK standard) plug at the wall end and a 6P4C or 6P2C [[modular connector]] at the telephone end: this latter may be wired as per the RJ11 standard (with pins 3 and 4), or it may be wired with pins 2 and 5, as a straight-through cable from the BT plug (which uses pins 2 and 5 for the line, unlike RJ11, which uses pins 3 and 4). Thus cables are not in general compatible between different phones, as the phone base may have a socket with pins 2 and 5 (requiring a straight-through cable), or have an RJ11 socket (requiring a [[crossover cable]]).

When [[modular connector]]s are used, the latch release of the connector should be on the ridge side of flat phone wire in order to maintain polarity.

Though four wires are typically used in U.S. phone cabling, only two are necessary for telecommunication. In the event that a second line is needed, the other two are used.  They are also sometimes used to provide power for telephone dial lamps (6 volts AC, as in the [[Princess phone]]), or other features.