One long-standing benefit of the PDF format is that it allows users to send documents for review in an uneditable format, so what happens to this property when editable objects like form fields, text annotations, comments and stamps are added to the document? Luckily, it's still possible to distribute the files in an uneditable format by flattening these objects to become part of the document.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.