\mathfrak - turn on fraktur font for uppercase and lowercase letters and digits (and a few other characters).
{ \mathfrak #1}
\mathfrak command is used to turn on fraktur font for uppercase and lowercase letters and digits (and a few other characters).
\mathfrak{ABCDEFGHIJKLMNOPQRSTUVWXYZ}
\mathfrak{0123456789}
\mathfrak{abcdefghijklmnopqrstuvwxyz}
\mathfrak{AB}AB