For Confluence wikis that are publicly available via the internet, Zen contains several tools for enhancing search engine indexing of your content.
For example, the active-image macro includes an accessible parameter that allows you to tag your image with header text, to assist search-engine indexing.
In addition, Zen contains the following SEO-specific macros:
Example
Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
Aliquam fermentum vestibulum est. Sed quis tortor.