Editing Trefoil (section)

==Symbols==
Symmetrical trefoils are particularly popular as warning and informational symbols. If a box containing hazardous material is moved around and shifted into different positions, it is still easy to recognize the symbol,<ref>{{cite web|url=http://www.hms.harvard.edu/orsp/coms/BiosafetyResources/History-of-Biohazard-Symbol.htm|title=Committee on Microbiological Safety - HMS|website=www.hms.harvard.edu|access-date=2 April 2018|archive-date=16 July 2011|archive-url=https://web.archive.org/web/20110716160837/http://www.hms.harvard.edu/orsp/coms/BiosafetyResources/History-of-Biohazard-Symbol.htm|url-status=dead}}</ref> while the distinctive trefoil design of the [[recycling symbol]] makes it easy for a consumer to notice and identify the packaging the symbol has been printed on as recyclable. Easily stenciled symbols are also favored.

<gallery>
File:Radiation warning symbol.svg|[[Hazard symbol#Ionizing radiation symbol|Ionizing radiation hazard trefoil]]
File:Fallout shelter symbol.svg|[[Fallout shelter]] trefoil
File:Biohazard symbol.svg|[[Hazard symbol#Biohazard sign|Biological hazard trefoil]]
File:Recycle001.svg|Universal [[recycling symbol]]
File:Pictogram_VORTAC.svg|[[VHF_omnidirectional_range|VORTAC Aircraft Navigation Beacon]]
File:WikiProject Scouting trefoil fade.svg|One particular stylized form of the heraldic trefoil is used as the main element in the logo of most [[Girl Guiding and Girl Scouting]] organizations. For Girl Scouts, the three trefoil leaves represent the three-fold promise: "To serve God and my country, to help people at all times, and to live by the Girl Scout law."
</gallery>

While the green trefoil is considered by many to be the symbol of Ireland, the harp has much greater officially recognized status. Therefore, shamrocks generally do not appear on Irish coins or postage stamps.

A trefoil is also part of the logo for [[Adidas Originals]], which also includes three stripes.