Reporting “brake wear”

Today, for the first time, the message “brake lining wear” came in the display. According to friendly people, the brake discs were already slightly lowered in the front in April, but still ok. That makes sense: first change after 40,000 km, now at 90,000 km that fits already. (Hints have held the brake discs 70,000 km). Now the question: does this message mean that (also) the brake discs are down, or does it really only mean the brake pads? These would be significantly cheaper to replace. Can it be that the pads are to be changed more often than the discs? I thought it was always exchanged. It also doesn’t stand there whether the front or the rear is the wear. In the most stupid case, I let everything change in the front and in truth only the pads are down at the rear… Either way or so: I never had this message before. Does anyone know that? Normally, the NL is changing rather early, so that it doesn’t come to the report at all.