While working on a change, I discovered that most people add handling for shorthands inside either StyleResolver or StyleBuilder (you can check that all of the shorthands are mentioned at some point). However we do expand most shorthands** to their longhands during parsing so all this code is effectively dead. The main issue is that people don't know about the previous expansion and thus repeat what the old code did. If we remove this code, we need to add some ASSERTs to ensure that people don't fall back into copying and pasting. ** The only exception is 'font' which is special due to system fonts (but we handle it in a way that is not compliant with CSS 3 Fonts)