Variants Puzzles and others: https://chessvariants.training/
https://altcodeunicode.com/alt-codes-math-symbols-italic-letters/
FoW: https://www.chess.com/blog/Illingworth/fog-of-war-chess-grandmaster-strategy
some crazyhouse study for future reference: https://lichess.org/study/OHSQPWgG
Klubid
4 Player Chess
51 018 liiget
Fog of War
5 771 liiget
Variants
4 525 liiget
8 Player Chess
921 liiget
4PC Teams
387 liiget