Editing Registered jack (section)

==RJ45S==
[[File:RJ45 female connector.jpg|thumb|upright|8P8C keyed female connector (jack), the same as that used in RJ45S]]

The RJ45S, an obsolete standard<ref>{{cite web |url=https://www.lifewire.com/definition-of-rj45-817872 |title=The Basics of RJ45, RJ45s, and 8P8C Connectors and Cables
|website=lifewire.com |access-date=22 November 2023 }}</ref> jack once specified for modem or data interfaces, has a slot on one side to allow mating with a special variation of the 8P plug: a mechanically-keyed plug with an extra tab on one side that prevents it from mating with regular (non-keyed) 8P jacks. The visual difference from the more-common 8P female is subtle. The RJ45S keyed 8P modular connector has only pins 5 and 4 wired for tip and ring (respectively) of a single telephone line, and a "programming" resistor connected to pins 7 and 8.<ref>{{cite web |url=http://pe2bz.philpem.me.uk/Comm/-%20Telephone/Site-900-Everything/Plugs/rj45s.html |title=RJ45S (Archived copy) |access-date=2017-05-22 |url-status=live |archive-url=https://web.archive.org/web/20180509184226/https://pe2bz.philpem.me.uk/Comm/-%20Telephone/Site-900-Everything/Plugs/rj45s.html |archive-date=2018-05-09 }}</ref><ref>{{cite web |url=http://www.hvs.on.ca/modular_jack_wiring.htm |title=Modular Jack Wiring |publisher=Hamilton Video & Sound Limited |archive-url=https://web.archive.org/web/20071014035210/http://hvs.on.ca/modular_jack_wiring.htm |archive-date=2007-10-14 |access-date=2017-05-21 |url-status=dead }}</ref><ref>{{cite web |url=http://www.siemon.com/us/standards/13-24_modular_wiring_reference.asp |title=Modular Wiring Reference |publisher=Siemon |access-date=2010-10-14 |url-status=live |archive-url=https://web.archive.org/web/20101008203926/http://www.siemon.com/us/standards/13-24_modular_wiring_reference.asp |archive-date=2010-10-08 }}</ref>