In Confluence 5.10, and 6.2, new languages were added to Confluence. However, indexing support for those languages were not added and so instances generating content in those languages would not be able to index and search them properly. We should add support for indexing these languages:

• Danish
• Spanish
• Italian
• Hungarian
• Dutch
• Norwegian
• Romanian
• Finish
• Swedish

If I have time remaining I'm going to look at strategies to support multiple languages in the same instance.

Note: Icelandic, Slovenian and Estonian are out of scope as there are no official analyzers from the Lucene project.
Polish is out of scope because parts of the Stempel analyzer from Lucene uses a non-standard BSD based license which our legal team is still evaluating.

Workaround

Change the "Indexing Language" of the site to "Other" in "General configuration" administration settings. This setting should work reasonably well, but not perfectly, for most languages.