Thread:Project:Support desk/Collaboration in MediaWiki

Hello everyone, I'm fairly new to Wiki world so my apologies if my question is stupid and that's why it isn't listed in the FAQ/Support Desk.

The company I'm working for has set up a small mediawiki which serves as a manual for a software application for both the employees of the company and external clients. Of course, only employees can edit the media wiki and external clients have read-only access over the internet.

For better collaboration on the mediawiki among the employees, I am looking for a way to annotate / leave comments in the wiki that can only be read by people within the company and not by people from outside / the clients.

I was thinking about some browser Plugin..? I checked several addons / plugins but they all require some sort of account and have way too many features which we don't need. Any suggestions / ideas?

Thank you in advance, Regards, Marc