Stig,
Indeed not necessarily a military B.II. In which case according to Kroschel & Stützer the company designation was a rather unoriginal DD. Yavor Dinkov has a photo captioned as DD at
https://www.flickr.com/photos/33497395@N08/8474802781
The same photo is in the relevant Aeronaut volume captioned as an early B.II! This volune also has a Sanke Card with the caption Albatros Militar-Doppeldecker. So not really helpfull?
I no longer think that the photo I linked to shows the machine as part of the Prinz-Heinrich-Flug as Zwickau was not a destination.
As For the B2, on a purely speculative basis could this be applied just for a competion and indicate a certain class of aircraft be it weight class,engine power or even as a biplane?,with the machine in the photo being the second entrant of the B 'Class' in the competion?
Incidently while searching I found this link to a crashed Taube from the 1914 Prinz-Heinrich-Flug
https://m.facebook.com/landesarchiv....690539/?type=3
Regards,
Clint