If you no longer want to use a trackable document category, you can disable it. Once disabled the category no longer shows when you upload a document. It also deselects all employees who were assigned to it, who would've been prompted tasks to provide the document.
As an admin user, click your name in the top right-hand corner, then click Settings.
On the General settings menu, click Employee data.
Click Trackable documents.
You are asked to confirm whether you want to disable it.
Click Disable trackable document type.
You can enable a trackable document category at any time. Follow the same steps as above, but click Enable instead.