When drawing a new icon for application is there some standard that says how much empty space should be left in each side of the icon? I mean that each icon reservers x*y pixels from the application shell. But visible image inside icon usually don't fill this whole place (at least when you look icons on s60 application shell).

Maybe there is some standard that says that leave 10% empty space for top or that image fills only 90% from the icon and rest of the space is transparent