|Metadata, conditional processing, and indexing / Indexing|
You can create a special ditamap which has a sole purpose of being the container for common indexterm elements for re-use in the prolog section of topics (and the topicmeta section of ditamaps, if required) through the conref feature.
Like most DITA elements, index elements can be re-used through the conref mechanism. There are good reasons why you might want to re-use index entries, including consistency of wording and punctuation, and reduced translation costs. (Even if used in more than one place, re-used index entries only have to be translated once in the conref source.)
You may find that you can better manage the re-use of index terms if they are stored in their own, standalone, ditamap. That index re-use ditamap will never be processed, and never embedded in another ditamap; it is only used for the purposes of re-use. Such a ditamap file should be named with a prefix of conref_source_. The ditamap could easily be used by many authors working in the same team.
<map id="conref_index_reuse"> <title>Index Term Re-use</title> <topicmeta> <keywords> <indexterm id="index_turbocharger">turbocharger</indexterm> <indexterm id="index_keypad_PIN">keypad <indexterm>PIN</indexterm> </indexterm> <indexterm id="index_immobiliser">immobiliser</indexterm> ... </keywords> </topicmeta> </map>