Back when I lived in Belgium (I left in 2004) reserve teams were not allowed in the normal league systems and played in a normal reserve league. Also provinciale teams had their reserve teams in a seperate league, for practical reasons often the exact same league compositions as the first teams. Only exception back then were OH Leuven whose reserves played in 4th provinciale but they were clever enough to register the reserve team with a different name and different matricule, so in theory it was a different club.
Today I accidently read that some Walloon team had to play their games on the same day as their reserve team in provinciale and both were supposed to play at home on the same pitch on the same time. Out of curiosity I checked the tables for the provinciale leagues of province Liege, and the whole 4th provinciales are full of reserve teams
They dont require seperate names and matricules anymore, they just use the name "FC Seraing B" for example. in some 4th provinciale divisions half of the teams were reserve teams, and some clubs in 1st and 2nd provinciale even have their reserve team in 4th provinciale ...
I did not know this was possible, when I was still in Belgium it was forbidden to have reserve teams in the regular leagues. Now even clubs such as FC Wasseiges have a reserve team in the regular provinciale divisions.
Is this decided on provincial basis where provinces can decide if they allow reserve teams, or is it nationally accepted now so that in every province some reserve teams will play in the lower provinciale divisons? Can these clubs promote or would it not be allowed to have for example Jong Lede B play in the same division as Jong Lede first team?
I am surprised they are allowing this in Liege. Imagine every club in Belgium wants his reserve team in the regular leagues, then the number of clubs in provinciale would suddenly double and we would need to have a 6th and 7th provinciale division to cope with all those reserveteams