code: def format_subject(subject):
      
      subject_prefix_re = r'^Re\[(\d*)\]:\ '
      m = re.match(subject_prefix_re, subject, re.U)
      prefix = u""
      if subject.startswith('Re: '):
          prefix = u"[2]"
          subject = subject[4:]
      elif m is not None:
          try:
              num = int(m.group(1))
              prefix = u"[%d]" % (num+1)
              subject = subject[6+len(str(num)):]
          except:
              # if anything fails here, fall back to the old mechanism
              pass
  
      return ugettext(u"Re%(prefix)s: %(subject)s") % {
          'subject': subject,
          'prefix': prefix
      }
docs: Prepends 'Re:' to the subject. To avoid multiple 'Re:'s
      a counter is added.
      NOTE: Currently unused. First step to fix Issue #48.
      FIXME: Any hints how to make this i18n aware are very welcome.