|Information types and topics / Information types|
The topic information type is the ancestor of all DITA information types, and is used mainly as the basis for specialising new information types.
All DITA information types have "evolved" from the topic proto information type. The topic type is weakly information typed, or even untyped, in that it has generic rather than semantic elements. It is designed as a starting point for specialisation, and not for use as a container for structured, semantic content.
Apart from for specialisation, the other purpose of the untyped topic information type is to store legacy information during the migration of style-based documents to DITA. For example, when migrating untyped HTML content to DITA, it can be useful to first convert HTML topics to untyped DITA topic, for later conversion to correctly typed DITA information types such as concept, task and reference.
The root element of an untyped topic is topic.