This command does the same as Convert|Characters|Characters ⇒  except that it replaces characters with hexadecimal references instead of decimal references. So “après-ski” becomes “après-ski”.
Convert menu
Convert|Characters|Characters ⇒ 
Convert|Characters|Characters ⇒ 
Convert|Characters|Characters ⇒ &htmlchar;
Convert|Characters|&htmlchar; ⇒ Characters
Convert|Characters|Reserved Characters ⇒ XML Entities
Convert|Characters|XML Entities ⇒ Reserved Characters
Convert|Text Encoding