NCC-73918 was the registry number of a Federation Danube-class runabout that was in service with Starfleet in the late 24th century, attached to Deep Space 9.
In 2375, Kira Nerys, Odo and Elim Garak used it to enter Cardassian space to assist the Cardassian Rebellion. Along with Damar and Rusot they later rendezvoused with a Cardassian shuttle. (DS9: "Tacking Into the Wind")
The name of NCC-73918 was illegible when the ship appeared on screen – just the registry was legible on the hull.