I was sent a PDF that has a text box on top of the image with a message in it. I was able to open it in Adobe Reader and move the box around. But apparently you cannot add such a box with Reader. Do you have to purchase the full Acrobat to achieve this one functionality or is there another way? BTW, I'm not talking about the note function that looks like a post-it. This was just a plain ole text box.
There are two kinds of text boxes in a PDF: a field and an annotation.
To be able to add any of them in Reader the file needs to have special rights granted to it in Acrobat.