Illustrated Glossary of Organic Chemistry

Cahn-Ingold-Prelog rules: A series of rules used to establish priority of attachments (lone pairs, single atoms, or groups) for purposes such as assigning R/S configuration to an sp3 stereocenter or E/Z configuration to an alkene.

Priorities: HO > CH3CH2 > CH3 > H
Name: (R)-2-Butanol

Priorities: I > CH3 and CH3CH2 > H
Name: (Z)-2-Iodo-2-pentene