\unicode - Used to implement a \unicode{} extension to TEX that allows arbitrary unicode code points to be entered in mathematics.
{ \unicode[optHeight,optDepth][optFont]#1 }
\unicode command implements a \unicode{} extension to TEX that allows arbitrary unicode code points to be entered in mathematics.
\unicode{x263a}
\unicode[.55,0.05]{x22D6}
\unicode[.55,0.05][Geramond]{x22D6}
\unicode[Geramond]{x22D6}