It seems like every BJD company has different names for different sizes of BJDs. From largest to smallest, for example, Volks goes SD17, SD16, SD13, SD10, MSD, etc. From largest to smallest, Iplehouse goes Elder, Senior, Youth, Junior, Kid, Baby. From largest to smallest, Souldoll goes Zenith, Double, Vito, Souloid, Kid, Sweet, Little. I'm personally amused by D-Storic's lineup, which starts with God [1:1 scale!], King, Queen, Rook, Bishop, Knight, Pawn.
Anyway, Fairyland gets my award for most confusing naming system. I'm writing a list of their sizes and names below because there are too many Fees and Pukis running around. And I can never keep LittleFees and MiniFees straight. MiniFees are the mature 40cms, while LittleFees are the child 25cms, but I think that the LittleFees should be larger than the MiniFees. ARGH!