I know that Ringeck doesn't describe the Nebenhut in great detail, it is, however, implied in a way that I have a pretty good clue about how it looks like.
Here's an image I found on the website:
This is in line with what Meyer says about the Nebenhut. (transcription courtesy of 'Die Freifechter')
[color="blue"]Nebenhut.
IN dise Hut schick dich also/ Stehe mit dem Lincken fuß vor / halt dein Schwerde neben der Rechten / mit der Spitzen auff der Erden / das der Knopff ubersich / und die kurtze schneid
gegen dir stehe.[/color]
Here's a translation:
[color="red"] Nebenhut
Assume this guard thus/stand with the left foot forward/hold your sword at your right (side)/with the point on the ground/so that the pommel is up/and the short edge is directed towards you. [/color]
So, Meyer describes it with the blade on the right side of the body, but -just like he says elsewhere- it can be done from both sides.
It's quite a natural position that comes from a diagonal downward blow, only 'cocked back' a little further so one can strike strongly upwards with long or short edge again.
Jörg