Since the antiquaries of the eighteenth century—Hunter, Gordon, and Horsley—identified the forts on Hadrian's Wall with the stations per lineam valli by means of inscriptions found in them, further epigraphic material has accumulated, as a result of which all the forts except those at Newcastle-upon-Tyne and Rudchester, as far west as Birdoswald, have produced evidence of the regiments assigned by the Notitia Dignitatum to the stations Segedunum-(C)amboglanna. But, in a number of instances, there have also come to light inscriptions set up by regiments that do not occur in the Notitia, or that are placed elsewhere in that list; the purpose of the present paper is to consider the significance of these inscriptions.