@classmethod
def section_tag(cls, symbol_or_re, is_re=False):
    """Make a section tag from symbol or regular expression.

        :returns: unicode string.

        :param symbol_or_re: symbol string or regular expresssion.
        :param is_re: if True, escape the delimiters for regular
          expressions.
        """
    return cls.adhoc_tag(symbol_or_re, cls.section_delimiters, is_re)
