The Imperial German railways (Reichseisenbahnen) allocated various steam locomotives in Alsace-Lorraine to the P 1 class of engines as follows:
Classification system from 1906/1912 Alsace-Lorraine B 1 Alsace-Lorraine B 2 Alsace-Lorraine B 3 Alsace-Lorraine B 4
See also Imperial Railways in Alsace-Lorraine List of Alsace-Lorraine locomotives