You can turn off these headers and footers using the following steps:

   In the Firefox menu, click Print… to open the print preview screen.
   Click the Page Setup… button.
   Go to the Margins & Header/Footer tab.
   Make sure that all dropdown menus are set to --blank--. 

If you only want to turn off those headers and footers for a specific printer, use these steps:

   In the Firefox address bar, type about:config.
   If a warning appears, click I accept the risk.
   Type print_header into this screen’s search box.
   Double-click on the relevant print_headerleft, print_headerright, and print_headercenter entries in the grid.
   Delete any existing data for that setting and click OK.
   Type print_footer into the screen’s search box and repeat these steps for the footer settings.

I am specifically asking for help with iOS. I don’t have a problem turning it off in Win or OSX. Thanks for the reply, but it doesn’t apply to my question.

It asked me what device & OS I was using when I was entering the question, I didn’t realize it wouldn’t post the question in the right forum or otherwise indicate what the specific situation was. Sorry!

Doesn’t work if one is printing to PDF. I need to make this work in PDF docs.