"This is a completely transparent (empty) image.

As a flag, it can be used on craft as physics-less decorative skin. 3 stock background patterns are available (white, black, orange), all of them are pretty neat. It's featured on my ES-107 SKYLON spaceplane.

To make it appear on the ES-107, download and save the image as "empty.png" in the following folder (or other place where your game is installed):
C:\Program Files (x86)\Steam\steamapps\common\Kerbal Space Program\GameData\Squad\Flags

You can give it whatever name you like and still be able to use it, but it won't show on the ES-107 or my other craft in that case."