In TeXForm#
TeXForm parses this entry as a character leaf mapped to U+03C0 (GREEK SMALL LETTER PI).
\bbalpha\bbbeta\bbchi\bbdelta\bbDelta\bbdotlessi\bbdotlessj\bbepsilon\bbeta\bbgamma\bbGamma\txtbfbbpi
\txtbfbbpiSymbol
The π symbol (Greek small letter pi, U+03C0), written as \txtbfbbpi in LaTeX text mode.