New indexing elements (see, see also, sort as)

DITA 1.1 supports the following new indexing elements:

<index-see>
<index-see-also>
<index-sort-as>

See and See also indexing elements

In DITA 1.0, you cannot specify the <see> and <see also> index entries by using the current <indexterm> element. The DITA 1.1 standard introduces the following new child elements for <indexterm> that support this functionality:

index-see
index-see-also

For example, you can add the kind of index entry shown below:

<indexterm>computer
   <index-see>monitor</index-see>
   <index-see-also>Illustration</index-see-also> 
</indexterm>

Then, if you generate HTML Help, JavaHelp, and PDF output with the indexing function enabled, the index entries will look like the following:

computer 43
        See monitor
        See also Illustration

In HTMLHelp and JavaHelp, the output will contain hyperlinks to the "see" and "see also" entries. In PDF output, the output is not hyperlinked.

See and See also indexing is ignored in XHTML. In PDF, you must enable indexing using the FO plug-in provided by Idiom.

Sort order indexing elements

With the DITA 1.1 standard, you can specify a sort phrase and sort index entries under the sort phrase. This feature allows you to sort an index entry in a way different from the default. One example would be to disregard insignificant leading text, such as punctuation or words like "the" or "a".

Another example would be to sort <data> under the letter D rather than the character "<", or to include such an entry under both the punctuation heading and also the letter D. In this case there would be index entry directives differentiated only by the sort order.

If you put the following content in the source file:

<indexterm>data<index-sort-as>key</index-sort-as></indexterm>
<indexterm>indextest<index-sort-as>abc</index-sort-as></indexterm>

the output should be:

indextest data

Another example might be a translation project in which a document needs to be translated into Japanese. Many of the index entries contain kanji, which need to be sorted in phonetic order. The translators, who can understand the language and see the entry in its context, can insert the <index-sort-as> elements into the <indexterm> elements as part of their localization work.

Supporting ICU in index sorting

With DITA Open Toolkit 1.3, you can get correctly sorted index output for different languages.

During normal transformation, the Toolkit looks for ICU (International Components Unicode) classes inside the classpath element. If the ICU is enabled, the Toolkit uses ICU's Collator class to do the comparing and sorting. If the ICU is not enabled, the Toolkit will use the JDK's Collator class to do the comparing and sorting.

Note: The ICU is included in the Toolkit 1.3 full installation package.