Subcategories help further categorise Content Categories. They can also be used across categories (although they always are attached to the original category).
Subcategories are created when creating an article.
In the Article Editing Window simply insert the name of the Subcategory you want to create into the Sub Category field and Save or Update the article when ready.
You should check to ensure that a similar subcategory does not already exists. It will be in the Sub Category drop down list immediately below the text field, if there is.
Select a subcategory from the aforementioned drop down list and proceed as normal.
There are two ways a subcategory can be edited.
Click on the Sub Categories link at the top of the Category area
Click on the selected sub category
Edit and Update as required or Return to Article Listing (if you do not want to edit)
Select a subcategory from the list in the Sub Category field.
Click Edit This Sub Category
Edit and Update as required.
Edit as necessary: