Salts or esters of carbamic acid, H2NC(=O)OH, or of N-substituted carbamic acids R2NC(=O)OR', (R' = hydrocarbyl or a cation). The esters are often called urethanes or urethans, a usage that is strictly correct only for the ethyl esters.
PAC, 1995, 67, 1307 (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1323