# File lib/locale/tag/common.rb, line 37
        def parse(tag)
          if tag =~ /\APOSIX\Z/  # This is the special case of POSIX locale but match this regexp.
            nil
          elsif tag =~ TAG_RE
            lang, script, region, subtag = $1, $2, $3, $4
            variants = subtag.scan(/(^|[-_])#{VARIANT}(?=([-_]|$))/i).collect{|v| v[1]}
            
            ret = self.new(lang, script, region, variants)
            ret.tag = tag
            ret
          else
            nil
          end
        end