premise: However, no testimony shall relate to unpublished material or information or to the reporters' motivations, bias, mental impressions, or other information extrinsic to what the reporter saw and heard, and the reporter shall not be obligated to reveal any confidential sources.
hypothesis: The omission of the identity of confidential sources is not allowed in a reporters' testimony.
reason: The written statement is worded in a way that suggests that a reporter is required to reveal their confidential sources, and this is not the case. The system was fooled by this due to the indirect wording of the statement.