What do the yellow, red and black cards mean in pentathlon fencing?

• Yellow: "A warning", after which any further offence brings a heavier penalty.
• Red in the ranking round: "a deduction of ten (10) Modern Pentathlon (MP) points".
• Red in the seeding round: one victory taken from the total.
• Red in the direct elimination: "one (1) hit awarded against the pentathlete".
• Black: elimination or disqualification for the athlete, or exclusion from the venue for anyone else.
• First group: a yellow first, then red each time. Examples: turning the back, leaving the strip to avoid a hit, causing body contact to avoid a hit, refusing to obey the referee.
• Second group: red every time. Examples: using the non-sword hand, a deliberate hit not on the opponent, dangerous or vindictive action.
• Third group: red, then black. Examples: disturbing order on the strip, tampering with equipment.
• Fourth group: black at once. Examples: cheating with equipment, collusion, deliberate brutality.
• The salute: refusing to salute or shake hands is a red card, and a black card the second time.
• Annulled hits: many offences also cancel any hit the offender scored.
• Not turning up: an athlete absent after three calls a minute apart is eliminated.

The glossary has fencing, the ranking round, the direct elimination, the one-hit bout, the modern pentathlon points entry and the pentathlete.

The three colours come from fencing itself and let a referee respond in proportion. The red card had to be translated for pentathlon, because a penalty hit would decide a one-hit bout outright. So in the pool rounds it costs points or a victory, and only in the knockout does it cost a hit.