#### 38.1.3 Deciding when to use PI markers

PI markers are to be used for things that cannot be specified in DITA, but need to be specified for the output type you are producing. They complement the DITA code, and under no conditions alter its meaning.

For example, you can use PI markers to do any of the following:

- Designate split points and extract extents for HTML (see §27.3.1 Designating split points).
- Insert WAI markup (see §34. Generating WAI markup for HTML).
- Provide ALink entries for Help systems (see §16.6 Providing related-topic links for Help systems).
- Identify context-sensitive help targets (see §16.10 Setting up Context Sensitive Help (CSH)).
- Assign alternate configuration values to individual tables, graphics, paragraphs, or character spans (see §42.2.2 Overriding settings with configuration PI markers).
- Assign outputclass values to elements where outputclass is not allowed by the DITA specification (for example, see §14.9.5 Mapping indexterms to variant indexes).

Wherever you can use a rule (such as a configuration setting), do so; where you cannot, use a PI marker.

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Next Topic: 38.2 Understanding effects of PI markers

Parent Topic: 38.1 Understanding DITA2Go PI markers

Sibling Topics:

38.1.1 Understanding DITA2Go PI marker syntax

38.1.2 Including special characters in PI markers