http://www.sitemaps.org/protocol.php

Sitemaps allow search engines to quickly index all of one's content, and also to figure out what content needs to be re-indexed. Many wiki's such as MediaWiki support this feature, and search engines like Google look for and use it. If you add or change a page, it allows a search engine to quickly index just the page which changed, and the engine does not have to crawl your entire site.

This would be a great feature to have for both Confluence & JIRA.