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.

DITA has no native presentation format. Tagging within DITA simply labels what the information is, and not what it looks like. A phrase within a sentence may be a window name, and that is how it is marked up. This approach is known as semantic mark-up. Whether a semantically marked-up phrase eventually gets displayed in bold, or in red, or in a box, or not at all, is determined later, outside the authoring process.

Documents are never displayed to the reader in DITA; DITA is not a presentation format. Content is almost completely separated from presentational form and delivery format. Wherever possible, context is also separated from content.

In order to make editing friendlier, many DITA editing programs display the DITA content in a graphical user interface. This approach is described as WYSIOO - What You See is One Option. What you see as a DITA author may be nothing like how the reader will perceive the document, but it is one display option! (WYSIOO is a play on the familiar term WYSIWYG, or What You See Is What You Get.)