def METHOD_NAME(self, name, value, content):
    """
    Append an attribute name/value into L{Content.data}.
    @param name: The attribute name
    @type name: basestring
    @param value: The attribute's value
    @type value: basestring
    @param content: The current content being unmarshalled.
    @type content: L{Content}
    """
    key = name
    key = '_%s' % reserved.get(key, key)
    setattr(content.data, key, value)