SongKong contains a Year field and an Original Year field. Usually the year field stores the year the date of the release your songs have been matched to, and then for each song the original year contains the date of the first release that each song was released on, so all songs matched to the sdame release wiuld have the same value for the Year field. But sometimes it is more interesting to know the original year than the year and this is accessible to more applications then if it is stored in the original year field.
Warning:If you do enable this option and you have SongKong configured to rename songs from filename then you should not use Year to name folders as part of the rename mask because this could cause your songs to be split into multiple folders since songs in a release can have different original release dates.