This document discusses predicate rules and how 21 CFR Part 11, which governs electronic records and signatures, relates to and must be interpreted according to underlying FDA regulations known as predicate rules. It provides background on the CFR and gives examples of predicate rules for areas like GMPs, GLPs, and GCPs. It explains that Part 11 only applies to electronic records that are required by predicate rules, and that predicate rules determine requirements around record creation, content, signatures, and retention. The document uses guidance from the Part 11 guidance document to illustrate how predicate rules should be referenced in determining Part 11 compliance.