register_printf_render
int register_printf_render(int spec, printf_render *render, printf_arginfo_function *arginfo);
register_printf_render(*specs,
register_printf_render(*specs,
register_printf_render(*specs,
register_printf_render(*specs,
register_printf_render(*specs,
register_printf_render('N',
register_printf_render('I',
register_printf_render('S',
register_printf_render('N',
register_printf_render('S',