The system defines four levels of threats represented by five colors: white, yellow, orange, red, scarlet. The levels call for specific security measures, including increased police or police/military mixed patrols in subways, train stations and other vulnerable locations.
"Vigipirate" is a portmanteau of "vigilance" (vigilance) or "vigie" (watchtower) and "pirate" (pirate).
Raise security levels to face real yet still uncertain dangers, through measures that are local and minimally disruptive of normal activity, while preparing to switch to "orange" or "red" within a few days.
Possible threat / prevent terrorist action
Take measures against plausible risks of terrorist action, including the use of means that are moderately disruptive to normal public activities, while preparing to switch to "red" or "scarlet" on short notice where possible.
High chance of threat / prevent serious attack
Take measures against a proven risk of one or more terrorist actions, including measures to protect public institutions and putting in place appropriate means for rescue and response, authorizing a significant level of disruption to social and economic activity.
Definite threat / prevent major attack
Notification of a risk of major attacks, simultaneous or otherwise, using non-conventional means and causing major devastation; preparing appropriate means of rescue and response, measures that are highly disruptive to public life are authorized.
^Mathieu Rigouste , « L’ennemi intérieur, de la guerre coloniale au contrôle sécuritaire », Cultures & Conflits, 67, automne 2007, [En ligne], mis en ligne le 04 janvier 2010. URL : http://conflits.revues.org/index3128.html