Nowrap is an excellent idea, I guess is would be extremely useful. Nevertheless the goal was to solve the "dotted lines into index summaries quiz" and I just found an alternative way to obtain what I needed, avoiding nowrap and covering too the case of text longer than a single row into a html box:
http://it.wikisource.org/wiki/Wikisource:Pagina_delle_prove#Ancora_puntiniI don't know if such a trick is "original" - it's so hard to discover something new into wiki...;-) - but I know that I'm searching for it from the beginning of my source trip. :-)