Unicode: 21A5. Infix arrow operator. x ↥ y is by default interpreted as UpTeeArrow[x,y]. Extensible character.
Unicode: 22A5. Alias: Esc uT Esc. Infix relational operator. x ⊥ y is by default interpreted as UpTee[x,y]. Used in geometry to indicate perpendicular. Used in number theory ...
Unicode: 2240. Infix operator. x ≀ y is by default interpreted as VerticalTilde[x,y]. Used in mathematics to mean wreath product.
Unicode: F725. Letter-like form. Used in yellow to indicate messages and other warnings in the default style for Mathematica notebooks. Based on an international standard ...
Unicode: 231A. Letter-like form. Used to indicate a calculation that may take a long time.
Unicode: 2118. Alias: Esc wp Esc. Letter. Used to denote the function WeierstrassP. Not the same as \[ScriptCapitalP].
\[Xi]
(Mathematica Character Name) Unicode: 03BE. Aliases: Esc x Esc, Esc xi Esc. Greek letter.
\[Xor]
(Mathematica Character Name) Unicode: 22BB. Alias: Esc xor Esc. Infix operator with built-in evaluation rules. x ⊻ y is by default interpreted as Xor[x,y].
Unicode: 00FD. Alias: Esc y' Esc. Letter. Included in ISO Latin-1.
\[Yen]
(Mathematica Character Name) Unicode: 00A5. Letter-like form. Currency symbol for Japanese yen, as in ¥5000.