What conditions does a PDF have to meet so annotations are allowed? I have a PDF for which the annotation menu remains greyed out regardless of whether I have Annotations / F6 checked.

A workaround for this is to flatten the PDF by saving it to another PDF file, the flattened one should be annotatable.

If the explanation is long and complicated, the workaround is fine with me. IMHO PDF has replaced Outlook as the Internet's **** Of Babylon in recent years. But dealing with PDFs is inevitable.

w

Maybe the PDF is protected.
On normal PDFs I can use Alt+5 (typewriter) to write on it. I don't use PDF so much, but i've never found a PDF where the annotation menu is grayed out