If a signature is not validated in a PDF, we see Validity unknown with a question mark. You need to validate the signature to make it valid.

How to Convert a Signed Signature to PDF. Adobe Acrobat is a powerhouse of productivity in the business world. It lets you create forms, documents, reports and presentations in the nimble PDF ...

Apple's Preview program in OS X is great for capturing signatures, but by default these can only be used with Preview; however, there is a workaround to extract and them for use elsewhere.

Signing documents the old fashioned way? Ditch that pen for good! Here’s how to easily create a digital signature using your phone.

This tutorial shows you how to enable and validate Digital Signature for PDF files in the Microsoft Edge browser. You can also view digital signatures in Edge.

First, create your signature (s): in Preview, choose Tools, Annotate, Signature and then Manage signatures. The dialog that appears lets you sign your name on the trackpad or use your Mac’s ...