Family crest
A family crest was a logo that represented a particular family. Klingons who wished to join another Great House needed to prove themselves worthy to wear that house's crest. (DS9: "You Are Cordially Invited")
In 2370, Worf confronted Lursa and B'Etor with their crest, which had been dropped by an assassin who tried to kill him. They suggested someone gave it to the assassin to use in order to frame them.(TNG: "Firstborn")
In 2373, Worf did not recognize Grilka when he first saw her, nor her family crest, and inquired which house she belonged to. (DS9: "Looking for par'Mach in All the Wrong Places")
Also that year, Martok noted Worf still wore the crest of the House of Mogh. Worf noted that Jadzia Dax called it a "sentimental gesture. Martok then offered to let him wear the crest of the House of Martok instead, which Worf accepted. (DS9: "Soldiers of the Empire")
In 2377, Kohlar inquired where B'Elanna Torres's family crest and images of Kahless. Torres explained that they clashed with the carpet. (VOY: "Prophecy")