Index redirection

The <index-see> and <index-see-also> elements enable redirection to other index entries within the generated index.

The <index-see> element contains text for an index entry that the reader should use instead of the current one, whereas the <index-see-also> element contains text for an index entry that the reader should use in addition to the current one.

Generated index entries should not contain both locators and redirections. Therefore, it is an error if the following conditions occur:

An <indexterm> contains <index-see>, and the publication contains other <indexterm> with matching content

An <indexterm> element contains an <index-see> element, and the publication contains one or more <indexterm> elements with matching textual content.

For example, topics referenced by the master map include the following markup:

<!-- Topic A -->
<indexterm>memory stick
  <index-see>USB drive</index-see>
</indexterm>

<!-- Topic B -->
<indexterm>memory stick</indexterm>

An <indexterm> contains <index-see> and <index-see-also>

An <indexterm> element contains both an <index-see> element and an <index-see-also> element.

For example, a topic contains the following <indexterm> element:

<indexterm>
  memory stick
    <index-see>USB drive</index-see>
    <index-see-also>flash stick</index-see-also>
</indexterm>

A processor MAY give an error message when it encounters the following error conditions:

An <indexterm> element contains an <index-see> element, and the publication contains one or more <indexterm> elements with matching textual content.
Both <index-see> and <index-see-also> elements within the same <indexterm> element.

Processors MAY recover from these error conditions by treating the <index-see> element as an <index-see-also> element.