[boost] printf official specs or docs, ISO C99, and C++

I found https://svn.boost.org/trac10/ticket/10541 today and my guess is Boost.Format hasn't been updated to support the ISO C99 extensions, or the Microsoft type formats. Before any work is done on this, I'm looking for any official C++ documentation related to printf support requirements. For example the compatibility section in http://www.cplusplus.com/reference/cstdio/printf/ indicates certain language levels have requirements. Thanks, Jim