Most facts come courtesy of CMR 74, Higgins & Gage
and Michel Ganzsachen-Katalog Europa Ost.

As yet, we concentrate on material until the
2nd currency reform

Jpgs come courtesy of;
Sorin Pantis, Mircea Dragoteanu,
Ing Chris Trevers, Classic Philatelics and Ebay.
More about military cards:
Dan Grecu: Romanian Postal History Page

Note for the amateur: Especially with classic postal cards
there are two varieties: single or double. (5B or 5B+5B (as an example))
Double cards consisted of a question and an answer part
and is mostly recogniced by notes at bottom explaining which part is which
Single cards have no such explanations