20 C.F.R. § 902.2 – Definitions.

(a) Records of the Joint Board. For purposes of this part, the term “records of the Joint Board” means rules, statements, opinions, orders, memoranda, letters, reports, accounts, and other papers containing information in the possession of the Joint Board that constitute part of the Joint Board's official files.
(b) Unusual Circumstances. For purposes of this part, “unusual circumstances” means, but only to the extent reasonably necessary for the proper processing of the particular request:
1. (1) The need to search for and collect the requested records from other establishments that are separate from the Joint Board's office processing the request;
2. (2) The need to search for, collect, and appropriately examine a voluminous amount of separate and distinct records which are demanded in a single request; or
3. (3) The need for consultation, which shall be conducted with all practicable speed, with another agency having a substantial interest in the determination of the request.