This is the description of the 1964 CR Classification System that
appeared in the January 1968 issue of the Journal of the ACM.
It appears here for historical reasons only. The 1964 CR system is
obsolete and has been supplanted by the 1991
System, which should be used for all new papers.
Introduction to the CR Classification System (1964 Version)
Two types of content indicators are to be assigned: category numbers
from the classification schedule used by Computing Reviews,
and free choice key words and key phrases consisting of English
language words.
To assign the CR category numbers consult the latest
CR classification schedule herewith, published in
CR, May-June 1967 issue, pages 302-303. Use as many category
numbers as may be applicable. If possible specify your interpretation
of the ``miscellaneous,'' or ``general,'' categories if these are
used. The following category numbers might, for example, be
applicable to a manuscript dealing with sorting techniques: 3.74
(searching), 4.49 (miscellaneous utility programs), 5.31 (sorting).
In listing key words and key phrases to be used for indexing, put
yourself in the place of the person who is looking for information in
your paper, and write down all the words that he might use in
searching an index. If you have a technical thesaurus available, such
as the IFIP-ICC Vocabulary of Information Processing
[North-Holland Publishmg Co., Amsterdam], consult it. Also consult
the citations to the relevant literature for helpful suggestions for
alternate key words. The key words and key phrases used should be as
precise as possible and hopefully unambiguous in their particular
context. Typically ten to fifteen words or phrases might be used. The
following additional guidelines may be of help.
- Use important terms from the title; include also their synonyms,
relsted words, and words of higher or lower generic rank.
- Use English nouns, or noun-noun and noun-adjective combinations;
do not use prepositions; do not use sequences of more than
three words; do not use hyphens except if the hyphenated parts are
always treated as a single unit.
- Use specific terms whose meaning is generally accepted in the
computer field; do not use broad catchall terms (such as
``computer,'' ``automatic,'' ``machine,'' ``system,'' ``discussion,''
``description''); do not use private terms or acronyms that may not be
generally known.
- Do not use negative terms stressing what your paper does
not do; emphasize the positive content and contribution.