Complex sentence: Until 1996, the league had two levels (Serie A1 e Serie A2) and a relegation/promotion system, although the teams promoted from the second level could participate in the championship play-off against Serie A1's first teams.
Split into simpler sentences: Until 1996, the league had two levels, "Serie A1" and "Serie A2", and a relegation/promotion system. However, the teams promoted from the second level could also participate in the championship play-off against Serie A1's first teams.