The full title of this paper is improved “Alpha-Tested Magnification for Vector Textures and Special Effects”. It’s about a technique to use vector textures when decaling for improved precision when magnificating. This kind of decal is useful for signs and such things that contains text or symbols because they can easily be represented as vector graphics. The left image below shows standard Alpha-Testing and the image on the right shows the improved version.

Link to the paper:
http://www.valvesoftware.com/publications/2007/SIGGRAPH2007_AlphaTestedMagnification.pdf