Smart Tags will enable you to easily embed signature field elements into a PDF or some documents in order to identify the location where you want elements such as signature or initials boxes to be placed.When a document with Smart Tags is uploaded to DocVerify from the portal, API, or the Salesforce App, elements such as signature boxes, initial boxes, etc. are automatically placed at the exact location that you specified with Smart Tags.
To learn how to use Smart Tags, please visit the Developer's page.