Soldier Regiment Unit?

[LDR]

Is it possible to tell from this photo what regiment/unit branch of service this soldier is from?
There are two photos of him. On one he seems to have been promoted. I can make out a unit number of 6 on the first photo...but is there any way of telling what branch?

Also what does it say on the first photo?

Thanks

lewis

[LDR]

Marriage photo:

[LDR]

CLose up:

[Simon O.]

On his marriage photo as feldwebel it looks like he might have the medical insignia. The waffenfarbe could well be medical blue which would place him in the pre-war Sanitätsabteilung 6

[LDR]

Thanks Simon. On closer inspection, it looks more like a U shape with a dot underneath.
Seems that its not really possible to tell the branch without other helping factors.