Thanks Galtego. I'll look into that.
Back to topic.
One of my sites [A] currently has only 2500 pages in Google's index, most of them showing nothing but URL in SERPS. It used to have 10 times that much, but since the site largely consists of listings, where almost every single page can is indexed under a lot of different keywords, has a lot of next-page, previous-page links and therefor can be reached with hundreds of different links,
the current number actually better reflects the actual number of content pages.
From another site [B], in a different language, I started supplying links to site A (about 760 different links to 760 different pages on site A). The URLs in these links are shorter, with only one variable, and those are the ones left in the index right now.
The problem is. None of these pages have title and description in serps.
As I see it ther reason must be that the that these links got a higher value thanks to the off-site links.
Google saw that these had duplicate content from the ones with longer URLs already in the index. Still valued the new links higher and ditched the old ones.
But for 2 months now, I've been waiting for the titles and descriptions for these pages.
Now, I guess I will just have to change site A so it also uses the shorter kind of links from site B. Except, that will not be appreciated by the users, who like to browse the site by page...