\[DottedSquare] (Mathematica Character Name)

Unicode: F751. Letter-like form.

\[DoubleContourIntegral] (Mathematica Character Name)

Unicode: 222F. Compound operator. ∯ f s is by default interpreted as ContourIntegral[f,s]. Used to indicate integrals over closed surfaces.

\[DoubleDagger] (Mathematica Character Name)

Unicode: 2021. Alias: Esc ddg Esc. Letter-like form.

\[DoubleDownArrow] (Mathematica Character Name)

Unicode: 21D3. Infix arrow operator. x ⇓ y is by default interpreted as DoubleDownArrow[x,y]. Extensible character.

\[DoubleLongLeftArrow] (Mathematica Character Name)

Unicode: 27F8. Alias: Esc <== Esc. Infix arrow operator. x ⟸ y is by default interpreted as DoubleLongLeftArrow[x,y].

\[DoubleLongLeftRightArrow] (Mathematica Character Name)

Unicode: 27FA. Alias: Esc <==> Esc. Infix arrow operator. x ⟺ y is by default interpreted as DoubleLongLeftRightArrow[x,y]. Not the same as \[Equivalent].

\[DoubleLongRightArrow] (Mathematica Character Name)

Unicode: 27F9. Alias: Esc ==> Esc. Infix arrow operator. x ⟹ y is by default interpreted as DoubleLongRightArrow[x,y].

\[DoublePrime] (Mathematica Character Name)

Unicode: 2033. Alias: Esc '' Esc. Letter-like form. Used to indicate angles in seconds or distances in inches.

\[DoubleUpArrow] (Mathematica Character Name)

Unicode: 21D1. Infix arrow operator. x ⇑ y is by default interpreted as DoubleUpArrow[x,y]. Extensible character.

\[DoubleUpDownArrow] (Mathematica Character Name)

Unicode: 21D5. Infix arrow operator. x ⇕ y is by default interpreted as DoubleUpDownArrow[x,y]. Extensible character.