View source for Recognition signal

[[File:HMS Belfast - Superstructure.jpg|thumb|[[HMS Belfast (C35)|HMS ''Belfast'' (C35)]] using [[International maritime signal flags]] as a recognition signal]]

A '''recognition signal''' is a [[wikt:signal|signal]] whereby a person, a [[ship]], an [[airplane]] or something else is [[wikt:recognize|recognize]]d. They can be used during war or can be used to help the police recognize each other during [[wikt:undercover|undercover]] [[wikt:operation|operation]]s. It can also be used in [[biology]] to signal that a [[molecule]] or [[chemical]] is to be [[wikt:bound|bound]] to another molecule.

==War==
These signals are often used to recognize friends and enemies in a war.<ref>{{cite web|url=http://www.gwpda.org/naval/gnto0400.htm | title=German Navy Tactical Orders (Enemy Recognition Signals)|access-date=2009-02-18|author=Commander-in-Chief High Sea Fleet (German navy}}</ref><ref>{{Cite web|title=Visual signals: Military communication without words|url=https://www.hprc-online.org/social-fitness/teams-leadership/visual-signals-military-communication-without-words|access-date=2022-02-10|website=HPRC|language=en}}</ref> For [[military]] use these signals often use colored lights or the [[International marine signal flags]].

==Police==
Other uses of the signal include the police who sometimes use a recognition signal so that officers in [[uniform]] can recognize officers in normal clothing (undercover).<ref>{{cite news |first=George |last=James |title=Police Agencies Share Rules for Recognition |url=https://query.nytimes.com/gst/fullpage.html?res=9C0DE2DB1239F937A1575BC0A962958260 |work=New York Times |date=24 August 1994 |access-date=2008-09-17}}</ref><ref name="Krauss">{{cite news|first=Clifford |last=Krauss |title=Subway Chaos: Officer Firing at Officer |url=https://query.nytimes.com/gst/fullpage.html?res=9C04E7DC1239F937A1575BC0A962958260&sec=&spon=&pagewanted=2 |work=New York Times |date=24 August 1994|access-date=2008-10-05}}</ref> The [[New York Police Department|NYPD]] often use [[headband]]s, [[wristbands]] or colored [[clothing]] as recognition signals which are known as the "[[Color of the day (police)|color of the day]]".<ref name="Krauss"/>

==Biology==
A recognition signal is also a [[chemical]] signal used in [[biology]] to signal the end of a section of [[DNA]] or [[RNA]] during [[gene]] [[wikt:duplicate|duplication]] in [[Cell (biology)|cell]]s.<ref>{{cite web |url=http://ukpmc.ac.uk/articlerender.cgi?tool=EBI&pubmedid=9450956 |title=Recognition Signal for C-Mannosylation of Trp-7 in RNase 2 Consists of Sequence Trp-x-x-Trp |author=Joachim Krieg |author2=Steffen Hartmann |author3=Anna Vicentini |author4=Wolfgang Gläsner |author5=Daniel Hess |author6=Jan Hofsteenge |access-date=2009-02-19 |url-status=dead |archive-url=https://archive.today/20120730012257/http://ukpmc.ac.uk/articlerender.cgi?tool=EBI&pubmedid=9450956 |archive-date=2012-07-30 }}</ref>

==See also==
*[[Communication]]
*[[International Code of Signals]]

==Notes==
<references/>

==External links==
{{commons category|International Code of Signals}}
* [http://www.tpub.com/content/aviation/14243/css/14243_95.htm Signalman manual]

{{DEFAULTSORT:Recognition Signal}}
[[Category:Communication]]
[[Category:Biological techniques and tools]]
[[Category:Military communications]]

== References ==
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