A docking clamp or mooring clamp was a mechanical device by which one object as held to another, such as a starship held in place while docked at space stations. Ships were unable to leave until the docking clamps were released.
In 2369, Odo suggested that Deep Space 9 explode its mooring clamps so that Captain Jaheel could not blow his ship apart when he was forced to stay due to the aphasia virus moving through the station. (DS9: "Babel")
While under the influence of the Saltah'na energy spheres, Major Kira Nerys sealed the docking clamps of the Valerian transport, believing it was shipping dolamide explosives. (DS9: "Dramatis Personae")
Docking latches, structural devices aboard Galaxy-class starships used to connect the saucer section to the stardrive section after a saucer separation, could be called docking clamps since they "clamped" shut the saucer section to the stardrive section. (TNG: "Hollow Pursuits")
The Type 11 shuttlecraft were equipped with dorsal docking clamps and an airlock. In 2375, a shuttle from the USS Enterprise-E used these to attach to a Federation mission scoutship piloted by lieutenant commander Data. (Star Trek: Insurrection)