Section 18.2 - Prohibition on combined category documents(a) The Director of the Federal Register will not accept a document for filing and publication if it combines material that must appear under more than one category in the FEDERAL REGISTER. For example, a document may not contain both rulemaking and notice of proposed rulemaking material.(b) Where two related documents are to be published in the same FEDERAL REGISTER issue, the agency may insert a cross-reference in each document.