The Committee chose instead to base its conclusions on a consideration of its own criteria.

Beyond regulations, a tremendous variety of written materials analyze, interpret, and discuss FDA's view of its statutory mandate. These documents include proposed regulations, preambles to proposed and final regulations, Compliance Policy Guides, guidelines, advisory opinions, letters to the regulated industry, Regulatory and Notice of Adverse Findings letters (both now called Warning Letters), records of court actions, speeches, press releases, and speeches given by FDA officials. At one time or another, FDA has used all of these materials as a way of implementing the law. The Committee concluded, however, that it would be impractical to examine all of them because (1) ensuring that all relevant documents had been discovered would be difficult, (2) all of these documents might not offer consistent advice, (3) no practical indexes or other means for retrieval exist except for hand searching, and (4) many of these mechanisms do not legally bind the agency. Accordingly, the Committee decided to examine only those mechanisms that FDA agrees bind it to a particular position.

FDA has outlined the procedure that the public may use to seek a formal advisory opinion on the agency's view of the laws it administers (21 CFR §10.85). According to FDA, an advisory opinion represents the formal position of the agency on a matter; except in unusual situations that involve an immediate and significant danger to health, the agency is obligated to act in accordance with the opinion until it is amended or revoked [21 CFR §10.85(e)]. In addition to advisory opinions issued through the procedure outlined in 21 CFR §10.85, FDA has also identified in that section a number of other documents to which it accords the status of formal advisory opinions (unless they are subsequently repudiated by FDA or overruled by a court):

1. Any portion of a Federal Register notice other than the text of a proposed or final regulation, for example, a notice to manufacturers or a preamble to a proposed or final regulation.

2. Trade Correspondence (TC Nos. 1 through 431, and 1A through 8A) issued by FDA between 1938 and 1946.

3. Compliance policy guides issued by FDA beginning in 1968 and codified in the Compliance Policy Guides manual.