§ 306. Evidence. 1. Irrelevant or unduly repetitious evidence or cross-examination may be excluded. Except as otherwise provided by statute, the burden of proof shall be on the party who initiated the proceeding. No decision, determination or order shall be made except upon consideration of the record as a whole or such portion thereof as may be cited by any party to the proceeding and as supported by and in accordance with substantial evidence. Unless otherwise provided by any statute, agencies need not observe the rules of evidence observed by courts, but shall give effect to the rules of privilege recognized by law. Objections to evidentiary offers may be made and shall be noted in the record. Subject to these requirements, an agency may, for the purpose of expediting hearings, and when the interests of parties will not be substantially prejudiced thereby, adopt procedures for the submission of all or part of the evidence in written form.

2. All evidence, including records and documents in the possession of the agency of which it desires to avail itself, shall be offered and made a part of the record, and all such documentary evidence may be received in the form of copies or excerpts, or by incorporation by reference. In case of incorporation by reference, the materials so incorporated shall be available for examination by the parties before being received in evidence.

3. A party shall have the right of cross-examination.

4. Official notice may be taken of all facts of which judicial notice could be taken and of other facts within the specialized knowledge of the agency. When official notice is taken of a material fact not appearing in the evidence in the record and of which judicial notice could not be taken, every party shall be given notice thereof and shall on timely request be afforded an opportunity prior to decision to dispute the fact or its materiality.