\[Prime] (Mathematica Character Name)

Unicode: 2032. Alias: Esc ' Esc. Letter-like form. Used to indicate angles in minutes or distances in feet. Used in an overscript position as an acute accent.

\[Proportional] (Mathematica Character Name)

Unicode: 221D. Alias: Esc prop Esc. Infix relational operator. x ∝ y is by default interpreted as Proportional[x,y]. Not the same as \[Alpha].

\[RightGuillemet] (Mathematica Character Name)

Unicode: 00BB. Alias: Esc g>> Esc. Letter-like form. Used as closing quotation marks in languages such as Spanish. Not the same as \[GreaterGreater]. Not the same as >. ...

\[RuleDelayed] (Mathematica Character Name)

Unicode: F51F. Alias: Esc :> Esc. Infix operator with built-in evaluation rules. x  y is by default interpreted as x:>y or RuleDelayed[x,y]. x  y  z groups as x  (y  z).

\[Sampi] (Mathematica Character Name)

Unicode: 03E0. Aliases: Esc sa Esc, Esc sampi Esc. Special Greek letter. Appeared after ω in early Greek alphabet; used for Greek numeral 900.

\[Sigma] (Mathematica Character Name)

Unicode: 03C3. Aliases: Esc s Esc, Esc sigma Esc. Greek letter. Used in TraditionalForm for DivisorSigma and WeierstrassSigma.

\[Square] (Mathematica Character Name)

Unicode: F520. Alias: Esc sq Esc. Prefix operator.  x is by default interpreted as Square[x]. Used in mathematical physics to denote the d'Alembertian operator. Sometimes ...

\[Sterling] (Mathematica Character Name)

Unicode: 00A3. Letter-like form. Currency symbol for British pound sterling, as in £ 5. Used in mathematics to denote Lie derivative.

\[SuchThat] (Mathematica Character Name)

Unicode: 220D. Alias: Esc st Esc. Infix operator. x ∍ y is by default interpreted as SuchThat[x,y]. x ∍ y ∍ z groups as x ∍ (y ∍ z). Not the same as \[ReverseElement].

\[Therefore] (Mathematica Character Name)

Unicode: 2234. Alias: Esc tf Esc. Infix operator. x ∴ y is by default interpreted as Therefore[x,y]. x ∴ y ∴ z groups as x ∴ (y ∴ z).