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DITA authoring concepts
Moving from style-based authoring to a structured authoring methodology such as DITA requires a radically different approach to writing.
Introduction to DITA
DITA is an XML standard, an architectural approach, and a writing methodology, developed by technical communicators for technical communicators.
Inheritance
Inheritance is a key technical feature of DITA, as it is inheritance that enables specialisation of information types.

Introduction
Information types and topics
Topics are the building blocks of modular documents, and organising topics by semantic information types is one of the architectural features of DITA.
DITA map files
Syntax and mark-up
Language and punctuation
Graphics and figures
Cross-referencing
Cross-references are a means of binding individual topics into a coherent and navigable document.
Content re-use
Metadata, conditional processing, and indexing
The DITA documentation process
DITA authoring concepts
Moving from style-based authoring to a structured authoring methodology such as DITA requires a radically different approach to writing.
- Introduction to DITA
  DITA is an XML standard, an architectural approach, and a writing methodology, developed by technical communicators for technical communicators.
  - History of DITA
    DITA was originally developed within the technical publications department at IBM, but was donated to OASIS in 2004. It is now maintained by the OASIS DITA Technical Committee.
  - The A in DITA
    DITA provides a standardised architectural framework for creating and maintaining content.
  - OASIS and the DITA Technical Committee
    OASIS is a not-for-profit standards body, and membership is open to all. To participate in the ongoing development of the DITA standard, you must join OASIS.
  - DITA features
    DITA incorporates features designed to improve the quality and efficiency of documentation.
  - Information typing
    Information typing is a methodology which underpins DITA. Information is structured by topics with content models appropriate to the nature of the content. The three base DITA information types are concept, task and reference.
  - Topic-based authoring
    Content in DITA is authored in topics, rather than in larger documents or publications. A DITA topic must make sense in its own right. A topic is authored as a unit, not as part of a larger document.
  - Modularity
    DITA enables modular document development. Not only can topics be re-used, but any group of topics or elements can be treated as a modular document component.
  - Minimalism
    Particularly for procedural documentation, DITA topics should be written following the minimalism approach. Information should be arranged in succinct, action-oriented topics that help readers to understand quickly what they need to know.
  - Structured authoring
    Structured authoring can mean many things, but in the context of this document, structured authoring means a standardised, methodological approach to content creation incorporating systematic labelling, modular, topic-based architecture, constrained writing environments, and the separation of content and form.
  - The separation of content and form
    Fundamental to structured authoring is the concept of the separation of content from presentation and delivery. The way a piece of text looks during authoring is irrelevant. The formatting and presentation are post-authoring considerations, and activities possibly not performed by a technical writer.
  - Where DITA fits...
    DITA is technically defined as an XML application, and is therefore built on XML language standards. XML itself is based on other character representation rules. DITA can also be used in conjunction with related standards and technologies.
  - Inheritance
    Inheritance is a key technical feature of DITA, as it is inheritance that enables specialisation of information types.
  - Conditions, filtering, variants and ditaval
    Many confusing terms are used to describe different parts of the conditional publishing process. Understanding the terms is key to understanding the concepts.
  - Techniques to learn
    Authors moving from style-based authoring to structured authoring in a DITA environment will need to build chunking, labelling and linking skills, and to understand the technique of separation of content and form.
- Distinction between format and style, and data and metadata
  In DITA, format has a different meaning to style. Likewise, the meanings of data and metadata are very different. These distinctions in meaning are important to understanding the broader concept of the separation of content and form.
- Specialisation
  Specialisation allows you to construct your own types of documents without losing the benefits of working within a DITA framework; in particular, you can maintain interchangeability.
- Generalisation
  When information in a specialised information type needs to be converted into the information type from which it was specialised, the process is known as generalisation.
- Constraints
  The constraints mechanism in DITA allows the use of elements and attributes in an information type to be restricted without needing to create a full specialisation. Constraints aim to simplify the authoring process by reducing the complexity of an information type.

Inheritance

Inheritance is a key technical feature of DITA, as it is inheritance that enables specialisation of information types.

In object-oriented programming, inheritance is a way to form new program module classes using classes that have already been defined. DITA is designed around the principle of inheritance. The DITA base content model shows that even the three base information types (concept, task and reference) evolve from the topic proto information type, and share a common base structure whose characteristics they inherit.

Information Type Content Model - Base — Figure 1. Evolution of base information types

This idea of inheritance continues down. A task's step element is based on topic's li element.

The DITA Language Reference records the inheritance of each element. For example, the step element's inheritance is shown as topic/li, indicating that a topic information type's li element is specialised to become task/step, a task information type's step element.

DITA's inheritance model makes it easy to specialise topics or special elements within topics. You only have to define how the element is different from its immediate ancestor.

This idea reminds us again of Darwinian theory.

Evolution of Man — Figure 2. Evolution of man and an information type