It is recommended to use the Adobe Acrobat Pro application to create your PDF documents. Adobe Acrobat Pro comes with an EchoSign document tool. That allows you to embed the code read by EchoSign into the PDF itself. If Adobe Acrobat is not available please use the following link to view the User Guide for the EchoSign.
I am unfamiliar with EchoSign Codes and how to use them.
EchoSign uses a set of codes that can help their system detect a specific function within the PDF.
When a document is uploaded and configured to use the EchoSign feature, it recognizes the requests and submits the document to Adobe EchoSign. Adobe then detects the document, converts any code that it recognizes in to an EchoSign document that will allow users to enter information and digitally sign the document. can be used within a regular word document.