All pieces of the troll armor set have duplicated "set bonus" description containing internal text instead of actual description. I can't check now, but I assume the same happens with other equipment with a set bonus. Mead bases have a similar issue with internal text, but no duplication.
This appears both in the crafting menu and in the inventory tooltip. It's probably supposed to be the buff effect's description.
No such issue in meads (at least minor healing), even though they also have those effect description boxes.

