Your space-removal stuff isn't necessary with my patch: just add a 'subst' filter to the value: # highway=motorway {name '${ref|subst: =>.|prefix:boxx} ${name}' | # '${ref|subst: =>.|prefix:boxx}' | '${name}' } That replaces each space in ${ref} with a dot; to remove the spaces completely, use ${ref|subst: =>} - or, equivalently, ${ref|subst: }. Which would be best in the default rule-set? Would it be useful to have some sort of regular expression filter? I could code that up quickly enough, and it's probably cleaner than having magic in Element.java. Also, I forgot to mention when I posted my patch: I'd appreciate suggestions for better mnemonics for the magic characters; also if anyone knows how to code the 6-bit switch, I'd like some clues as to to how to find what encoding we're writing.