Thank you for the replies.
In the first place, I thought as well there should be some kinds of mark on the disc, but I couldn't find anything... until I read your messages... and checked again (more carefully)
...Embarrassing
...
You are right, not only it is written "schwungradseite" in German (it is a LUK clutch), but it is also engraved "Flywheel side"...
Sorry for that. If we were living close by, I would pay my round of beers at the corner's pub!
And Kev, you are right, the offset side is on the pressure plate side
Well done!
Thanks again.