Apparently it is possible to write a web page such that it pops up the printer dialogue on load. That is, something in the page automatically launches the print dialogue. Usually that is wanted/expected behavior. For example, you just clicked on a "Print" button on the page. In my case, there is one page I use a lot that tries to auto-print a PDF. But I have PDF's set to open outside of FireFox. So the PDF loads in Acrobat (expected behavior), and FireFox tries to print the HTML page that is open in FireFox. Also presumably expected behavior, but not wanted if it is the PDF I want to print. This has gotten annoying, and so I'm looking for a control that suppresses printing. Ten minutes of googleing and all I can find are articles for the control to suppress the dialogue for printing, and instead print directly to the default printer, ie silent printing. I don't want to suppress the dialog. I want to auto-cancel the print job. That is, I want to disallow a web page from invoking the print dialog at all, by overriding the print instruction. Such as setting could either be set for a specific page, set or globally; either would work for me. Is there a control for that?