http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47756
--- Comment #6 from Olaf van der Spek <olafvdspek at gmail dot com> --- Hi Jonathan, The difference between < > and " " is implementation defined. AFAIK GCC only searches the include path with < > and first searches relative to the current file with " ". So the standard can't offer better guidance. Let's consider GCC on Linux. Do you use < > only for standard C / C++ headers or do you also use it for for example zlib and other platform provided headers? What do major coding styles say?