The text string that appears in the keyword index.
An optional text string used when sorting the index. The sort key influences where the text appears in the keyword index. The sort key string does not appear in the keyword index.
Choosing the Index button in a general help dialog box displays a help index. Adding index entries to help topics is important because a user can search the index for a word or phrase to find help on a subject.
Either the <idx> start and end tags or the short form can be used.
The <sort> element changes the sort order for an index entry. Specifically, the <sort> element is used within the <idx> element to request that the keyword appear at the location indicated by the sort key string. No end tag for <sort> is required.