It is highly suggested to build a taxonomy to improve search relevancy and SEO. The taxonomy consists a list of tags. You can use those tags to tag the knowledge.
To manage tags, click the "Manage Tags" link on the side bar. Page "Manage Tags" is shown as follows.
You can add the top category by clicking the button "Add top level category".
Click the node, a popup menu is displayed, you can add a child for the current node, delete the node or edit the node.
Click the "Save" button to save the taxonomy. There is no DRAFT mode for taxonomy.
When you edit a knowledge item, you can add tags to the knowledge.
Click Button "Add tags" on the page "Edit Knowledge".
Select tags for current knowledge item and click "Ok" button. If all the children of a tag are selected, only the parent tag is displayed. When publishing the knowledge, all the selected tags including the children will be generated and assiciated with the knowledge item.
It is NOT recommended to have a huge and complex taxonomy. User may experience performance problems.