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
- Organisation of DITA elements
  Elements in DITA are grouped together into a number of categories for organisational and comprehension purposes.
- Working with mark-up
- Element domains
  Elements in DITA are arranged into domains for organisational purposes and technical reasons.
- Short descriptions
  The short description (or shortdesc) is arguably the most important component of a DITA topic, and is also one of the most difficult elements to write. Short descriptions should be written for every topic.
- Lists
  The purpose of a list is to make it easier for the reader to understand sequences of information and collections of like information. Different types of lists are used for different information structures.
- Paragraphs
  Paragraphs are the basic components of topics. A paragraph (p) element should be a self-contained unit dealing with one idea or point, typically expressed in two or more related sentences. The p element should be used when no other semantically-specific block element is available.
- Procedures and steps
  The purpose of procedural documents is to explain to the reader how to accomplish tasks. The task information type is specifically designed for procedures, with a well-defined structure built around steps.
  - Semantics in steps
    The steps of a procedure are defined in a task topic. Task topics typically have a simple structure of a single set of steps, but some procedures may require a more sophisticated structure that includes substeps and decision points.
  - Separating procedures into granular steps
    Steps within a task topic must be written so that a single step contains just one user action (known in DITA as a command).
  - Restricting tasks to one procedure only
    Task topics can only contain one procedure, with one continuous set of numbered steps.
  - The prereq element
    The pre-requisites (prereq) element describes the status or situation that must be established before a procedural task can be started. It can contain cross-references to pre-requisite task topics.
  - Substeps within steps
    Task topics allow two levels of steps within a single procedure: steps and substeps. Where possible, substeps should be avoided.
  - Single step procedure
    A procedure or task containing just one action should be marked-up using the normal steps/step/cmd structure.
  - The command element
    The command (cmd) element within the step element contains a single, active voice instruction to the reader.
  - Required and optional steps
    The importance attribute of a step is used to indicate whether an element is optional or mandatory.
  - Complex nested tasks
    A complex process made up of a number of procedures can be documented by collecting, through the ditamap, the constituent task topics under a process stub topic.
  - Notes and extra information in a step
    Information that supplements or supports a procedural step can be included within an info element. The info element in turn can contain block elements such as note elements.
  - Images within steps
    Images that support a procedural step can be included within a stepxmp or an info element.
  - Choice tables
    A choice table is used within a step in a task topic to describe a series of optional choices that a user must make before proceeding.
  - Non-sequential procedural steps
    Some procedures are not made up of sequential procedural steps. When documenting these procedures, the steps-informal structure or the steps-unordered structure should be used.
- Tables
  The purpose of a table is to structure, organise and present factual data that a user will need to look up or reference. There are two general purpose table types in DITA: table and simpletable.
- Phrases
  The semantics of words and phrases in DITA content is expressed through a broad range of phrase elements.
- Special characters and dates
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.

Complex nested tasks

A complex process made up of a number of procedures can be documented by collecting, through the ditamap, the constituent task topics under a process stub topic.

Tasks are sometimes differentiated into procedures and processes, where processes are high level overviews of a set of procedures, while procedures are detailed instructions for performing a task.

A process could be documented using a task information type, with each step of the process correlating to a procedure.

Schematic showing structural relationship between process and procedures — Figure 1. Structural relationship between process and procedures

While it is possible to hyperlink the individual steps of the process to the corresponding procedure topic, this is not recommended. Nor is it recommended to provide a related-links section in the process topic to link to the related procedure topics.

Best practice is to leave the high level process topic as a stub topic, with minimal information in it (typically just a title and a short description). The information type of the process topic should be either concept or task. The procedure topics should be arranged as child topics of the process topic in the ditamap, with the collection-type attribute of the process (parent) topic set to sequence. This arrangement will result in the process steps being automatically generated during processing, with the steps based on the titles of the child procedure topics. Any short descriptions in the procedure topics will also be included with the process steps. The sequence setting will result in the generated links being arranged in to a numbered list.

The stub topic approach to processes allows for much easier re-use, and removes re-keying of process steps. If one procedure is not used in a particular publishing scenario, the process topic won't need to be edited at all.

Example of a stub topic (with just a title and a short description) after processing, — Figure 2. Example of a stub topic after processing