The M1915/16 officer's undress tunic, der kleine Rock, was preferred by those officers who typically worked indoors, especially staff officers. The double-breasted tunic sported a turn-over collar, plain back vent, and 
two rows of six plain domed gold or silver buttons (Bavarian tunic: seven rows). The fabric was normally of superior quality doeskin or tricot. 

The tunic's cut was similar to that of the M1903 double-breasted Litewka, the officer's off-duty lounge jacket. The noticeable differences were that the Litewka was lighter in shade and had straight-cut side pockets, while the kleiner Rock was a darker feldgrau with diagonal-cut side pockets.

In addition to the term der kleine Rock, one might see this tunic referenced as kleiner Rock, or in a phrase such as Offizier im kleinen Rock.