Since i like the story of the Shadow rift from Ravenloft very much, i was wondering, if there ever was a discussion about their place in the Plane of Shadow. In the codex there was no entry (or i didn't find it...).
If someoneever worked out more about their background (and their mysterious creator/leader) and origin, i'd be happy to read it.
Hilsen!
Yeah. I am very sure, that there never was anything published in PS.
I only wanted to know, if someone wrote somethingon his/her own. 'cause as they are formally citizens of the demiplane of shadow, they are - in some way - part of the setting.
But I did not knew, that there was a vRG. Good hint. Thanks!
Indeed! The vRG sounds great (just read something about it).
Bah! True shadow elves are from Mystara, and are way cool. Who can't like the idea of subterranean albino elves who have a valid reason to be ruthless and badass, and who tap the latent magic from an extradimensional spaceship that crashlanded into the planet 6,000 years ago? 
Best part is, WotC has the source available as a free download. And you can grab a copy of the map from here, if you're interested.
I don't know anything about them, personally. Well, I know that White Wolf published a Von Richten's Guide to Shadow Elves. That might help.
There wasn't anything about them in Planescape materials.