"In this email from 2003, Richard Stallman says 'I've talked with our lawyer about one specific issue that you raised: that of
using simple material from header files. Someone recently made the claim that including a header file always
makes a derivative work. That's not the FSF's view. Our view is that just using structure
definitions, typedefs, enumeration constants, macros with simple
bodies, etc., is NOT enough to make a derivative work. It would take
a substantial amount of code (coming from inline functions or macros
with substantial bodies) to do that.' This should help end the recent FUD about the Android 'clean headers.'"
