In TeXForm#
TeXForm parses this entry as a character leaf mapped to U+03B2 (GREEK SMALL LETTER BETA).
\bbalpha\bbbeta\bbchi\bbdelta\bbDelta\bbdotlessi\bbdotlessj\bbepsilon\bbeta\bbgamma\bbGamma\bfbbbeta
\bfbbbetaSymbol
The β symbol (Greek small letter beta, U+03B2), written as \bfbbbeta in LaTeX math mode.