I noticed that at least two of the archives in the lichess database have PGNs with game notation that starts with "0..." instead of the typical "1.". I can't find any documentation on this format, and lichess's own PGN parser doesn't seem to be able to handle them. Does anyone have any info on this format?
Archives that use this format:
https://database.lichess.org/standard/lichess_db_standard_rated_2024-10.pgn.zst
https://database.lichess.org/standard/lichess_db_standard_rated_2018-03.pgn.zst