what are gflags of net_device for?

Hi all, Any idea for what do we need gflags of net_device? I believe gflags stand for global flags (though the header file, netdevice.h, does not say so explicitly). I see that they are initialized only in __dev_change_flags() , in net/core/dev.c, in But it is not clear what is their meaning. Any ideas? can someone elaborate on this ? rgs, Andy