Tracer Bullet or tracer bullet may refer to: Tracer ammunition, bullets that are built with a small pyrotechnic charge in their base Tracer Bullet, a fictional detective, alter ego of Calvin in the comic strip Calvin and Hobbes A term used in Scrum (software development) to describe a proof-of-concept deliverable Pathfinder (library science) - a term for those pathfinders produced by the Library of Congress. See also Tracer (disambiguation) Bullet (disambiguation)