The CA Issue Indexes

Each Chemical Abstracts issue contains three indexes  

All these indexes, but particularly the Keyword Index, differ from the half-yearly volume indexes. The entries in the issue indexes are extracted fi om the abstract text, not from the original literature. Thus, these indexes do not provide such in-depth and systematic coverage as the volume indexes. 

The Keyword Index consists of a series of words and phrases selected from the title and text of the abstract (Fig. 16). Subject terms and substance names are listed alphabetically. The substance names included in the Keyword Index seldom correspond to the systematic CA Index Names. They can be trivial or semi-systematic names, but are, in each case, the designations used by the author in his paper and thus also included in the CA abstract. Only the volume indexes of the Chemical Abstracts contain the systematic substance names. 

The issue indexes are indispensable in the search for the most up-to-date literature, as it is not always possible to wait for the publication of the volume indexes. It is, however, advisable to repeat the search with the aid of the volume index, as the systematics of the volume indexes offer greater reliability. 

The Patent Index is arranged in an alphabetic list of the ISO codes of the countries in which the patents were issued. Within the listing for each country the patent numbers are arranged in numerical order. The principle of the Patent Index, which was introduced in 1981 to replace the Numerical Patent Index and the Patent Concordance, is to document the complete history of the patent family relating to each patent. The recently added members of the patent family are printed in bold face. A special situation occurs with US patents after submission of the patent application it is possible in the USA to request additional claims. These additional claims receive their own patent number but can keep the priority date of the origin patent, the origin patent can be canceled but does not have to be. The degree of interrelationship is indicated by the addition of phrases like related, non-priority or continuation-in-part. 

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The largest discrepancy in terminology between CA abstracts, the CA issue index and the appropriate volume index occurs in the substance names. The Chemical Substance Index employs only the systematic CA Index Names for substances, not the trivial or semi-systematic names generally used by an author in his paper. The Chemical Abstracts Service assigns systematic CA Index Names to each substance mentioned in Chemical Abstracts and to all... 

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