Longest individual notation?

I think you can do Qdxe8++ , checkmate

Dunno if anyone already wrote this (it's seven pages), but in ye olden times notation was like: "White plays his king's bishop to queen's bishop four." So be glad it isn't that.

*Qdxe8#

QB4c4462323b64193cb638nr314nz1843m46mrf2zjkc#

++ is used for double check, and of course a Queen move cannot be a double check.

I think you can do something like Qd7xe6++ or Qd7xe6#.

Qd7xe6# is 7 characters

Wait, can you add 1-0 to the end of your post?

Like, Qd7xe6#1-0 without space

No

I think the longest is dxe3++e.p. 8 non-period characters. (Chess.com doesn't write double check or en passant, but this does)

If u wanna see fxe8=#q, complete Feb. 4, 2024 in chess.com puzzles/

dxc8e.p.=Q+ maybe?

Almost quite! Except that en passant captures don't happen at the seventh and eighth ranks.

What is "++" is it a double check

actually if you had doubled pawns on the file you could actually write something like c7xd8=Q#

No.

maybe if you manipulate the board so this could happen, it could be like
2372. exd8e.p.=Q#1-0 (20 including spaces and periods, 18 without periods, 17 without space or periods.)
including some methods like move number, en passant, 1-0 (win) and pawn promotion?

if you manipulate the board, you could probably get en passant on 8th rank

chess.com lets you manipulate the board and the rules.

dxc6ep dxc6ep#!! (!! means enable commentary and ep means en passant