I have heard of "taping hinge lines", if elevator or flap hinge lines have too much space between them. How is it done?
The way to tell if the hinge lines have too much space between them is to attempt to move the surfaces -- if they move, there's too much space and you should tape the hinge lines.
(Except -- Brett Buck has claimed that it's not too much gap, but too much variation in the gap. And the effect of that variation goes down dramatically with gap size. So if you did something really odd, like space your flaps 1/8" away from your wing TE, then maybe you wouldn't need tape. Or maybe you'd just lose, who knows?