The tagging system is super easy to use - you don't have to create tags or delete them.
Click on the "Tags" button on the task window side menu.
You can set color to tags after you have assign them to the task. Click on the tag name on the left side of the task window.
Tags are shared across all projects. That way you can start using existing tags in new projects and avoid making duplicate tags with similar names.
You can only see tags from the projects that you have access.
If a tag is not attached to any task it will be automatically deleted.
Administrators can manage and see all tags on the tag management page.
To open the tag management page:
You can add new tags, remove, assing color, and rename tags from here.