It is now clear! NHK from Japan no longer confirms reception reports of the national medium wave broadcasts! In my case it was JOBB NHK from Osaka that I heard in Belgium on 828 kHz. All a shame of course… It is nice, however, that they make the effort to inform the DXer about this (on a card that could also have been used as QSL hi). I also received a program sheet. My homemade QSL (but not stamped or signed) was also back in the envelope! Fortunately, I can still keep a nice recording with a clear ID and the National Anthem of Japan between in the transmission of Pravoslavnoye Radio!: JOBB-NHK RADIO 2, Osaka, Japan 828 kHz.