Perfidy in the context of "Protective sign"

In human interactions, good faith (Latin: bona fidēs) is a sincere intention to be fair, open, and honest, regardless of the outcome of the interaction. Some Latin phrases have lost their literal meaning over centuries, but that is not the case with bona fides, which is still widely used and interchangeable with its generally accepted modern-day English translation of good faith. It is an important concept within law and business. The opposed concepts are bad faith, mala fides (duplicity) and perfidy (pretense).

A suicide attack (also known by a wide variety of other names, see below) is a deliberate attack in which the perpetrators intentionally end their own lives as part of the attack. These attacks are a form of murder–suicide that is often associated with terrorism or war. When the attackers are labelled as terrorists, the attacks are sometimes referred to as an act of suicide terrorism. Military use of suicide is not directly regulated by international law, but suicide attacks sometimes violate prohibitions against perfidy or targeting civilians. Suicide attacks have occurred in various contexts, ranging from military campaigns—such as the Japanese kamikaze pilots during World War II (1944–1945)—to more contemporary Islamic terrorist campaigns—including the September 11 attacks in 2001. Suicide attacks have been used by a wide range of political ideologies, from far-right (Japan and Germany in WWII) to far-left (such as the PKK and JRA).

Bad faith (Latin: mala fides) is a sustained form of deception which consists of entertaining or pretending to entertain one set of feelings while acting as if influenced by another. It is associated with hypocrisy, breach of contract, affectation, and lip service. It may involve intentional deceit of others, or self-deception.

Some examples of bad faith include: soldiers waving a white flag and then firing when their enemy approaches to take prisoners (cf. perfidy); a company representative who negotiates with union workers while having no intent of compromising; a prosecutor who argues a legal position that he knows to be false; and an insurer who uses language and reasoning which are deliberately misleading in order to deny a claim.

The French ruse de guerre, sometimes literally translated as ruse of war, is a non-uniform term; generally what is understood by "ruse of war" can be separated into two groups. The first classifies the phrase purely as an act of military deception against one's opponent; the second emphasizes acts against one's opponent by creative, clever, unorthodox means, sometimes involving force multipliers or superior knowledge. The term stratagem, from Ancient Greek strategema (στρατήγημα, 'act of generalship'), is also used in this sense.

Ruses de guerre are described from ancient to modern times, both in semi-mythical accounts and in well-documented events; they also feature in fiction. The term ruse de guerre is given legal meaning within the rules of war. Good faith is required, but at least 17 different types of ruse, including ambushes, false radio messages, the use of spies and the use of dummy guns, are considered legitimate as long as they do not involve treachery or perfidy. Landmines and similar traps can be considered perfidious under the rules in certain circumstances. Explicitly prohibited ruses under article 23 of the Hague Convention of 1907 include improper use of a flag of truce or the military insignia of the enemy.