G.2.3 Info Format: Printindex

Indices in Info format are generally written as a menu (see Indices), but with an additional directive at the beginning marking this as an index node:

    <printindex> =
^@^H[index^@^H]
* Menu:

<index entry>*

The <index entry> items are similar to normal menu entries, but the free-format description is replaced by the line number of where the entries occurs in the text:

    <index entry> =
* <entry text>: <entry node>. <lparen>line <lineno><rparen>

The <entry text> is the index term. The <lineno> is an unsigned integer, given relative to the start of the <entry node>. There may be arbitrary whitespace after the colon and period, as usual in menus, and may be broken across lines. Here is an example:

^@^H[index^@^H]
* Menu:

* thunder:           Weather Phenomena.             (line 5)

This means that an index entry for ‘thunder’ appears at line 5 of the node ‘Weather Phenomena’.