In TeXForm#
TeXForm parses this entry as a character leaf mapped to U+005D (RIGHT SQUARE BRACKET).
\bbalpha\bbbeta\bbchi\bbdelta\bbDelta\bbdotlessi\bbdotlessj\bbepsilon\bbeta\bbgamma\bbGamma\txtbfbbRbrack
\txtbfbbRbrackSymbol
The ] symbol (Right square bracket, U+005D), written as \txtbfbbRbrack in LaTeX text mode.