Commodities for which reports are required under these regulations are set forth in appendix A to this part. Any change therein will be made by publication in the Federal Register of an amendment thereto, and, in addition, announcement of such change will be made through the press service. The unit of measure to be used in reporting the commodity, the beginning and ending dates of the marketing year for each commodity, and any other information deemed necessary to be included in the report will be specified in appendix A to this part and amendments thereto and in the announcements through press service.