I'm currently working on an on-screen keyboard as part as the GUI for a set-top box (for typing in passwords, urls etc). I have found that there seems to be a pretty consistent use of symbols/icons for function keys such as Backspace, Shift and Space on existing physical keyboards and mobile devices. So these symbols are pretty well known amongst users. For instance, an outlined up-arrow as the shift symbol.
However, I also need a 'Clear all' (or 'Reset') button, and we are having some discussions on our team as to how a Clear symbol/icon on such a button should look since we've found no consistent references. Is there an often used symbol that I have missed out on, or does anyone here have a clever idea how to illustrate the function? Note: Graphics are shown in small sizes on TV's so small detailed graphics is not ideal.