The named templates in html/reasonlost.xsl fails to properly handle opening and closing square brackets for the fourth guideline example in supplementforlost.xml, namely:
τὸ[ν] Διο]γένην
should be
either
τὸ[ν] [Διο]γένην
or
τὸ[ν Διο]γένην
for
τὸ<supplied reason="lost">ν</supplied> <persName><supplied reason="lost">Διο</supplied>γένην</persName>
square brackets
Fixed by rviglianti in November 2011.