Unicode: 2195. Infix arrow operator. x ↕ y is by default interpreted as UpDownArrow[x,y]. Extensible character.
Unicode: 296E. Infix arrow-like operator. x ⥮ y is by default interpreted as UpEquilibrium[x,y]. Extensible character.
Unicode: 2196. Infix arrow operator. x ↖ y is by default interpreted as UpperLeftArrow[x,y]. Extensible character; grows by default to limited size.
Unicode: 2197. Infix arrow operator. x ↗ y is by default interpreted as UpperRightArrow[x,y]. Extensible character; grows by default to limited size.
Unicode: 03C5. Aliases: Esc u Esc, Esc upsilon Esc. Greek letter.
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: 22EE. Letter-like form. Used to indicate omitted elements in columns of a matrix.
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.