HtmlTools.encodeId makes id lower case

HtmlTools.encodeId uses Character.toLowerCase to convert its argument to lower case. I don't see the reason for that since upper case characters are legal in id's (see http://www.w3.org/TR/html4/types.html#type-name ). In particular, it's a problem with anchors/links in the xhtml sink (see DOXIA-47 ), especially if we want to create anchors from section names, to maintain backward compatibility with m1. Is there a special reason for the toLowerCase or can we remove it?