Russian Second League

The Russian Second League (Russian: Первенство России II дивизиона ФНЛ), formerly the Russian Professional Football League are both the third (Division A) and fourth level (Division B) of Russian professional football.
In 1998–2010, it was run by the Professional Football League. The 2011–12 season was run by the Department of Professional Football of the Russian Football Union (Russian: Департамент профессионального футбола Российского футбольного союза (ДПФ РФС), Departament professional'nogo futbola Rossijskogo futbol'nogo soyuza [DPF RFS]). From 2013 to 2021 season the league was again run by the Professional Football League and the name Second Division was no longer used, the league was just called PFL. Before the 2021–22 season, the league was merged organizationally with the second-tier First League and renamed to FNL2. Before the 2022–23 season, its short name was changed again, to a historical name "Russian Second League", even though the league's full title ("Second Division of the Football National League") remained the same.
The Second League was geographically divided into 4 zones: 1 (ex-South - Southern European Russia), 2 (ex-West - Western European Russia and Eastern Siberia), 3 (ex-Centre - Northern and Eastern European Russia and Sakhalin), 4 (ex-Ural-Povolzhye - Southern Urals and Western Siberia). The number of clubs in each zone varied between years. In the 2020–21 season, there were 64 clubs in the division.
The winners of each zone were automatically promoted to the Russian First League (known before 2011 as the First Division and from 2011 to 2022 as Russian Football National League). The bottom finishers of each zone lost professional status and were relegated to the Russian Amateur Football League. The teams typically could avoid relegation as long as they still have necessary financing to stay in the FNL2. Each club plays its opponents twice home and away.
For the 2023–24 season, the league was reorganized once again and split into two tiers - third-tier Russian Second League Division A and fourth-tier Russian Second League Division B.
Division A consists of two groups of 10 teams each - Gold Group and Silver Group. In the first stage of the season (summer/autumn), each team in the Gold and Silver groups plays each other team in the same group twice, home-and-away, for 18 games in total for each team.
For the second stage of the season (spring/summer), Groups are re-constituted. Gold Group now includes the top 6 first-stage Gold Group teams and top 4 first-stage Silver Group teams. Silver Group includes bottom 4 first-stage Gold Group teams, 5th and 6th-placed first-stage Silver Group teams and four winners of the Division B groups. Bottom 2 first-stage Silver Group teams are relegated to Division B. 7th and 8th first-stage Silver Group teams play in relegation play-offs against the previous season's bottom two second-stage Silver Group teams, with the losers of the play-offs relegated to Division B and the winners remaining in Division A Silver Group for the second stage. The teams in re-constituted groups play each other twice more for 18 more games. Top 2 Gold Group teams at the end of the season are promoted to the Russian First League for the next season. The 3rd-placed Gold Group team plays in promotion play-offs (two games, home-and-away) against the team that finishes first in the Gold Group in the first stage of the season (or second-placed first-stage team if the first-place first-stage team finishes in the top 2 or the bottom 4 in the second stage, or third-placed first-stage team if the second-place first-stage team also finishes in the top 2 or the bottom 4 in the second stage), the winner of those play-offs is also promoted to the Russian First League. The bottom four teams in the Gold Group at the end of the season are moved to Silver Group for the next season, and the top four teams in the Silver Group are moved to the Gold Group.
Division B consists of four groups, mostly based on geography (1, 2, 3, 4). The winners of groups 1, 2, 3 and 4 are promoted to the Division A Silver Group for the spring/summer part of the Division A season. Division B switched to the spring-to-autumn cycle, the season is played from March to November.
The rotation between Division A and Division B is happening in the winter, as described above.