A KWIC index is formed by sorting and aligning the words within an article title to allow each word (except the stop words) in titles to be searchable alphabetically in the index. It was a useful indexing method for technical manuals before computerized full text search became common.
For example, the title statement of this article and the Slogans would appear as follows in a KWIC index. A KWIC index usually uses a wide layout to allow the display of maximum 'in context' information (not shown in the following example).
|KWIC is an||acronym for Key Word In Context, ...||page 1|
|... Key Word In Context, the most||common format for concordance lines.||page 1|
|... the most common format for||concordance lines.||page 1|
|... is an acronym for Key Word In||Context, the most common format ...||page 1|
|Wikipedia, The Free||Encyclopedia||page 0|
|... In Context, the most common||format for concordance lines.||page 1|
|Wikipedia, The||Free Encyclopedia||page 0|
|KWIC is an acronym for||Key Word In Context, the most ...||page 1|
|KWIC is an acronym for Key Word ...||page 1|
|... common format for concordance||lines.||page 1|
|... for Key Word In Context, the||most common format for concordance ...||page 1|
|Wikipedia, The Free Encyclopedia||page 0|
The term permuted index is another name for a KWIC index, referring to the fact that it indexes all cyclic permutations of the headings. Books composed of many short sections with their own descriptive headings, most notably collections of manual pages, often ended with a permuted index section, allowing the reader to easily find a section by any word from its heading. This practice is no longer common today.
Note: The first reference does not show the KWIC index unless you pay to view the paper. The second reference does not even list the paper at all.