There was no Belgium before 1830 (and after that it ought to be Belgique or België depending on the region). Before 1830 it is generally possible to have a town, region, country - except for the Prince-Bishopric of Liège, I think.
Since 1977 many Belgian municipalities have merged: example: Klerken, gemeente Houthulst, West Vlaanderen, België.
Parentheses are often used where I live. For the département in France, ex: Brest (Finistère) or for the canton in Switzerland, ex. Payerne (Vaud).
Thanks for your efforts. I reiterate my wish to keep the present rule (use localities names as they were there and then).