Open the PDF file in either Adobe Acrobat or Adobe Reader. Click "Document" on the toolbar at the top of the program, scroll down to "Comments" with the cursor and select "Add Sticky Note." ...

Adding Sticky Notes and Highlighting a PDF Select the Sticky Note tool from the Annotations panel. Click, or click and drag, on a PDF document page to create a note.

Making sticky notes an early, built-in application of Mac computers, Apple found a way to bring these notes to the modern era, by featuring them as a great way to add reminders to your desktop.