What are permission tags?

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

Each permission group consists of one or more permission tags. These tags will display when an authorized user sets permissions to one or more assets in the Lytho asset manager. Assets with permission tags can only be viewed by users from a permission 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?