What are permission tags?

Assets with a permission tag are only visible for users located in a group with that specific permission tag assigned.

Permission tags can be assigned to user groups. These permission tags will be visible when an authorized user is willing to set permissions to one or more assets in the Lytho asset manager. Assets with permission tags can only be viewed by users from a specific group with the assigned permission tags. It is important to give a permission tag a short and self-contained name so the authorized user knows which users can, or can not view the edited asset when adding a specific permission tag.

How to add permission tags to an asset?