From your username I guess you're dutch? Which may be relevant context to why you / people you know refer to the non-Flemish Belgian comics (and perhaps things

From your username I guess you're dutch? Which may be relevant context to why you / people you know refer to the non-Flemish Belgian comics (and perhaps things other than comics?) as 'Franco-Belgian' if using French language while assuming that 'Belgian' without the specifier means Dutch language? I.e. the same way we all, wherever we're from, add extra words to define stuff that's not our default expectation ("a new neighbour moved in" if they're someone from the same place as us vs. "a new dutch neighbour" moved in if they're from that other country; or buying cheese in the shop vs. buying french cheese), just as a (subconscious often) time saving measure that there's no need to give the adjective when it fits the normal expectation. Not that I'm an expert on the international nomenclature of bande dessinée comics - though anecdotally, as a Brit (England, not Brittany haha) who grew up reading Asterix and above all Tintin, I thought of them (and think my parents called them) separately as French and Belgian respectively.