I can try verbs on them, but get the usual "that doesn't work" or "that's just plain silly" etc.
You can pick up the troll's sign and carry it in your inventory, but can't do anything with it.
The game finished just fine and the story was complete, I was just wondering.
I did have to look up hints a couple times (only 2 or 3), and in that walkthrough the author mentioned not being able to find a purpose for the sign either.
I think that was the GB walkthrough actually.
