HTML Purifier 4.11.x is a maintenance release, collecting a year
and a half of accumulated bug fixes.  Most notable fixes are
compatibility with PHP 7.3, and case-sensitive matching for
the SafeScripting whitelist.  There are a number small feature
enhancements, including an expanded supported color list,
initial and inherit support for {min-,max-,}{width,height}
and multidimensional array support for purifyArray.