Length in m - Displacement in mm
The default behaviour of the application is to use the International Unit system, which defines length unit as meter. And this is also used for displacements in results.
But it's comfortable to be able to use mm for displacements in results. To achieve this, you can simply define your prefered units in your profile. Just change the displacement unit, and set this system as the default one.
Once done, every structure will open with this default unit system, with a simple option to switch back to the i.s. system, or any another one, directly from the draw interface.