Notice of any proposed rule making is to be published in the Federal Register, including a statement of the time and place of the rule making proceedings and the terms or substance of the proposed nile. After notice the agency is to afford interested persons an opportunity to participate in the rule making. There are, in essence, three differing modes of participation, which have varying degrees of formality. Most administrative rules are subject to notice and comment: the proposed rules are published and interested parties can proffer written comments. Other niles are subject to formal rule making - a full trial-type hearing, which can include the provision of oral testimony and cross-examination. Yet other rules are governed by a hybrid process, which entails more formality than notice and comment,but less than the trial-type hearing.