BRT (later BRTN, later still VRT) - National channel in Flemish.
The devolution in Belgian society along language lines continues with two separate state broadcasters providing 2 services each in their own language.
BRT = Belgium Radio/Television; BRTN = Belgium Radio/Television in Dutch; VRT = Flemish Radio/Television
RTBF 1 and 2 - National channel in French
The separation is so total that RTBF "went commercial" some years before BRTN even considered it. This may be to do with the competition - RTBF v TF1 and BRTN v Nederland 1.
The '21' ident is from Tele21, identified by correspondent Nathalie Decker as a previous identity for RTBF2.
RTBF = Radio/Television Belgium in French
The above pictures were caught - mainly through DX reception - in the 1980s