def add_acl(self, scope, user, permission):
return self.send('<STR_LIT>', scope, user, permission)<EOL>
Add an `ACL <https://www.dokuwiki.org/acl>`_ rule that restricts
        the page/namespace *scope* to *user* (use *@group* syntax for groups)
        with *permission* level. It returns a boolean that indicate if the rule
        was correctly added.