Stiletto be employed along with the dagger as a fighting weapon; a 1536 dueling treatise authored by Achille Marozzo, "Opera Nova", contains sections on dagger and stiletto fighting. By the time of the Renaissance, the term stiletto had come to describe a range of slender thrusting knives closely resembling the French poignard, many with conventional dagger-profile blades and sharpened edges, but always retaining the slim profile and needle-like point. To lighten the weapon, many stilettos were equipped with blades carrying fullers over a portion of their length. The stiletto remained a popular weapon of criminals or political assassins from the 16th
Stiletto fallen or severely wounded heavily armored opponent. The needle-like blade could, if used with sufficient force, penetrate most mail or find its way through gaps in a knight's plate armor, and was narrow enough to pass through the eye slits of the helmeted knight. A severely wounded opponent who was not expected to survive would be given a "mercy strike" (French "coup de grâce"), hence the name "miséricorde". Later, the Gunner's Stiletto became a tool for clearing cannon-fuse touch holes; used in the manner of an automotive oil dipstick, they were often inscribed with marks indicating levels of powder charges