Chemical Nomenclature and Subject Term Selection Aids:
1. "Index Guide" to Chemical Abstracts.
This should be the first place you look before beginning either
a manual or computer-based subject search. Each five-year col-
lective index period has its own Index Guide volume. Although
the Chemical Abstracts database is in one huge file on some
vendors' systems, you still need to be aware that for a retro-
spective search which crosses the boundaries of collective index
time periods (1967-71, 1972-76, 1977-81, 1982-86, etc.), the
terms which were used at the time the printed product was pro-
duced are still the terms in the database. Thus, two entirely
different controlled vocabulary terms may be used to search for
information on the same concept or even the same chemical com-
pound, depending on the time an article or other primary work was
pub lished. The Index Guide contains cross-references and index-
ing policy notes to guide you to the controlled vocabulary for
both chemical substances and general subjects. However, not
finding an entry in the Index Guide does not mean that you should
not use that term. In fact, it means that you probably should
use the term or phrase. A full set of Index Guides is also
shelved with the collective indexes to Chemical Abstracts.
2. CA Headings List: General Subjects and CA Headings List:
Plants and Animals (May 1985).
Index headings and cross-references for the Ninth Collective
Index period (1972-76), the Tenth (1977-81) and the Eleventh
(1982-86) periods are listed in these volumes. Thus, it is
possible to find in one place the changes in terminology which
have occurred for general subjects, plants, and animals.
3. Registry Handbook-Common Names (1984).
This is a microfiche set which allows you to find a registry
number and molecular formula using a relatively uncomplicated
name for the substance. The Name Section has chemical names from
the CAS Registry Nomenclature File. There is also a Number
Section which lists both the CA Index Names (prefer red names) and
common substance names in the Handbook. The Number Section also
tells you when a particular CA Index Name was used in CA. Locat-
ed in the metal Kodak file on the Computer Reference Shelves.
4. New and Revised Chemical Abstracts Indexing Terms 1982 and
These documents describe changes which took effect at the begin-
ning of the 12th collective index periods, for General Subject
Index headings and class es of substances.
5. Qualified Substances in the CA File (June 1985).
A chemical substance is said to be "qualified" if it is one of
the ap proximately 600 substances which are found so frequently in
CA that its registry number is linked with one of seven standard
qualifiers. These are:
Uses and miscellaneous
Thus, the main type of information in a document about a
substance in the list is entered into a database using one of the
seven terms or phrases.
6. Search Aid for Name Searching Frequently Posted Name Seg-
ments in the Registry File (April 1985).
Name segments for chemical substances can be searched in the CAS
ONLINE Registry File. Name segments with more than 1000 postings
are listed in this booklet. For example, the term METHOXY is
actually segmented into two parts, METH and OXY.
7. Standard Abbreviations, Acronyms, Special Characters and
Symbols in CAS Computer-Readable Files and Publications (1982).
Abbreviations have been used for certain terms both in the index-
es and abstract text of CA. It is important to include relevant
abbreviations, etc. in a computer-based search.
8. Subject Coverage and Arrangement of Abstracts by Sections in
Chemical Abstracts (1982 edition) and Supplement.
This manual gives the guidelines and policies which identify
the subject content of the 80 CA sections into which printed
primary materials are div ided according to their subject content.
Summaries of changes in various sections over the years are found
in the supplement. Copies may also be found with the Index
Guides on the CA Collective Index shelves.
9. Ring Systems Handbook (1984).
The handbook contains structural diagrams and related data for
nearly 60,000 unique representative CA index ring systems. It
also includes data on cage systems. A "Ring Formula Index"
provides access by the number of rings in the compound and the
number of atoms comprising those rings. There is also a "Ring
Formula Index" by molecular formula. The entries provide the
registry numbers of the unsubstituted rings which could be used
in a Registry File search as the starting point for a complex
ring compound. Shelved with the CA Collective Index volumes.
10. Medical Subject Headings--Supplementary Chemical Records
This publication contains approximately 23,000 chemical com-
pounds mentioned in journals covered by Index Medicus and the
computer database MEDLINE.
11. CA Condensates and CASIA Search Aids (1975, 1976).
These microfiche sets contain various lists of words and
frequency counts of their occurrence in certain older Chemical
Abstracts volumes. On the basis of the relative frequencies of
occurrence of these terms, one may be able to predict the rela-
tive size of the sets which they would retrieve.