In TeXForm#
TeXForm parses this entry as a character leaf mapped to U+00B5 (MICRO SIGN).
\bbalpha\bbbeta\bbchi\bbdelta\bbDelta\bbdotlessi\bbdotlessj\bbepsilon\bbeta\bbgamma\bbGamma\txtbfbbmu
\txtbfbbmuSymbol
The µ symbol (Micro sign, U+00B5), written as \txtbfbbmu in LaTeX text mode.