You must have administrator access to manage tags.
Login to Admin Area, click Tools, choose the Tags tab.
From here you can see all the tags used in KB.
The following are compulsory:
You may also wish to:
A visible tag displays in the Tags of and article (below the article) in the Public Area. Although hidden tags do not display in the Tags section, it is always used for searching.
Yes, you can. When you update a tag it will affects all entries already assigned.
Conversely, when you delete a tag, it will be deleted from all entries that is was assigned to.
Since the daily scheduled tasks are responsible for updating meta keywords updates it might take some time for these changes to take effect.