Belgian Locomotive in German Service

[taube]

Gentlemen,

here is a photo depicting a Belgian locomotive in Imperial German service.
http://www.bundesbahnzeit.de/page.ph...mpf_in_Belgien

I would like to find out about the abbreviation: Mob. M. A. Cambrai
Question is if the lettering is German or maybe formely French/Belgian?

Cambrai is in France, of course.
It was an important railway knot for the German army.

Thanks in advance,
taube.