Open the Highlights tab in the left-hand pane and click Create a tag.
You can also create new tags by highlighting text in a document (right-hand pane) and click [new highlight]
This screen pops up where you can select an existing tab or create a new one.
Select text within a document and click [new highlight]
In the pop-up that appears, chose an existing tag or create a new one.
Each highlight can have multiple tags.
Create a hierarchy among your codes by using any punctuation marks like this:
Category
Category.subcategory or Category-subcategory.
You need to be in the Highlights tab on the left-hand pane/
To merge or delete tags or change the tag name, click on the edit button to the right of the tag.
You can make your changes on the pop-up screen.