Intentional Design Inc.

DITA, DTDs, FrameMaker, and other tools

A couple of people have asked lately what the difference is between a DTD and DITA, and in one case FrameMaker vs XML, so I thought the topic of schemas was worth discussion. Here, we’ll cover what a DTD really means, how to compare it to a DITA schema, and figure out where an authoring tool like FrameMaker fits in the picture.

On the scale of big-picture vs small-picture comparisons, the scale is:
- First: structured and unstructured content
- Second: DTD and DITA
- Third: FrameMaker and other authoring tools

We’ll start in the middle, with DTDs and DITA, and in future posts, discuss the first and third comparisons.

DTD and DITA

DTD stands for Document Type Definition. This is actually a misnomer, because the DTD doesn’t define the document type, it defines the document’s structure, so should be called Document Structure Definition. This file, which works in the background, enforces the structure of a document.

For example, you decide that a procedure in a User Guide has 1 heading, followed by 1 paragraph, followed by numbered steps, which could each contain a table, note, or graphic. Your DTD would enforce this standard by limiting the options that an author could choose at any given point.

Similarly, DITA is a Topic Structure Definition. Because DITA is topic-based, not document-based, this file enforces the structure of each topic. DITA comes with four topic types, and can be specialized as needed.

An easy way to explain DITA is to compare it to online help. If you were to learn how to write online help from a theoretical point of view, you would learn about writing concept topics, task topics, and reference topics, and how to link between them. These would be structured into a TOC. These are the exact topics in DITA: task, topic reference, plus a catch-all “generic” topic. And in the DITA vocabulary, a TOC is a DITA map.

Next post: Structured vs unstructured content