Which equipment items cannot be dropped from boss bonus?

Question

Hello,
As tibia.com says:

This bonus only applies to items which can be equipped unless they are limited to one drop per boss kill, e.g. Ferumbras' hat. Such unique drops are not affected by this bonus.

With this knowledge, using boss bonus on bosses like: Zushuka, The Welter or even Mad Mage (who drops mage's cap) is pointless? Or these items are not limited to one drop per boss?

Answer 1

As you mentioned, unique tiems are not affected by boss bonus but Tibia also said that they are not going to publish any list of "unique items" but they answered some questions at the forum:

Here is the link if you want to check the all the conversation:

https://www.tibia.com/forum/?action=thread&postid=39325583#post39325583

But here is good information they given to us: