Chemical Abstract Service Registry Number defined

CAS CHEMICAL REGISTRY 8,000,000 compounds CHEMICAL ABSTRACTS SERVICE The world s largest file of substance information, including coordination compounds, polymers, incompletely defined substances, alloys, mixtures, and minerals. In each record, the registry number is linked to molecular structure diagram, molecular formula, CA index name, synonyms, and the ten most recent references in Chemical Abstracts. Easy crossover to the bibliographic file... 

In general, for each substance, an unambiguous and unique name was chosen as the preferred name. For organic substances, it is usually one of the various systematic names recommended by lUPAC [79IU1]. A few other systematic names and widely used trivial names were adopted as synonyms. The symbols used to denote the natural elements are those recommended by lUPAC [91IU1]. Each substance is characterized by its chemical name and by its Chemical Abstracts Service (CAS) Registry Number to allow a well-defined search where chemical names are difficult or different chemical names are in common use. The CAS-registry number can be searched for in all disk files without difficulty. 

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