To print an index means to include it as part of a manual or Info
file. This does not happen automatically just because you use
@cindex or other index-entry generating commands in the
Texinfo file; those just cause the raw data for the index to be
accumulated. To generate an index, you must include the
@printindex command at the place in the document where you
want the index to appear. Also, as part of the process of creating a
printed manual, you must run a program called texindex
(see section Format and Print Hardcopy) to sort the raw data to produce a sorted
index file. The sorted index file is what is actually used to
print the index.
Texinfo offers six different types of predefined index: the concept index, the function index, the variables index, the keystroke index, the program index, and the data type index (see section Predefined Indices). Each index type has a two-letter name: `cp', `fn', `vr', `ky', `pg', and `tp'. You may merge indices, or put them into separate sections (see section Combining Indices); or you may define your own indices (see section Defining New Indices).
The @printindex command takes a two-letter index name, reads
the corresponding sorted index file and formats it appropriately into
an index.
The @printindex command does not generate a chapter heading
for the index. Consequently, you should precede the
@printindex command with a suitable section or chapter command
(usually @unnumbered) to supply the chapter heading and put
the index into the table of contents. Precede the @unnumbered
command with an @node line.
For example:
@node Variable Index, Concept Index, Function Index, Top @comment node-name, next, previous, up @unnumbered Variable Index @printindex vr @node Concept Index, , Variable Index, Top @comment node-name, next, previous, up @unnumbered Concept Index @printindex cp @summarycontents @contents @bye
(Readers often prefer that the concept index come last in a book, since that makes it easiest to find.)