Comment by mc10

Yeah I guess it depends on how sophisticated the "hiddenness" of the field is. Instead of straight up using the hidden property (which is easier for a bot to detect), you could try other things, like moving the input field offscreen and using overflow: hidden, or styling it such that it's the same color as the background and is unfillable. Now though you'll need to worrying about tabbing through fields (change tabindex to -1) and screen readers that might pick up the fields.