Lowest division = 3rd Division A + B

League system:
2 divisions (A and B).  Div A = 16 teams and Div B = 15 teams.
Each team plays each other twice.

The two Champions (from A and B) earn promotion to Division 2.
Normally teams placed 2nd –> 4th earn a place in the play-offs. (that’s 3 teams from A and 3 teams from B).
The winners of the 1st, 2nd and 3rd periods (“the first period” = first 10 games of the season, “the second period” = next 10 games of the season and “the third period” = last games of the season) gains a place in the play-offs.  And these period winners have priority over the 2nd–>4th placed teams.
The play-offs are quarter/semi/final stages played with the 2 teams from div 2 that play for relegation from 2nd division to 3rd division and the 6 teams from DIV A and B.

Period 1: Ronse = period title
Period 2: La Louvière = period title
Period 3: La Louvière = period title
Final standing in Division3 A
1. La Louvière (champion and direct promotion)
2. RC Mechelen
3. RC Waregem
4. Torhout
5. Ronse

Qualifiers for the playoffs from DIV3 A:
RC Mechelen, RC Waregem and Ronse (1st period title > 4th place)

A: bottom two teams relegated
B: bottom team relegated
The two teams in 14th position play the relegation playoff (Is in fact the promotion playoff from 4th Divisions A, B, D and D.

Match squad restrictions:
At least 2 under 21-players.

The only cup simulated is the Belgian Cup.
Teams from Div3 A&B start in round 3.
There are 7 rounds before the quarter finals.
Division 2 teams start in round 4
Division 1 teams start in round 5

U19 and U21
U21 = no competition simulated for DIV3 (only for DIV1)
U19 = competition in 4 groups (Groups 3 and 4 being the teams from Div3 A & B)

Source: Phil “I’m Brian (I’m divorced)”