TYPO3-Documentation/TYPO3CMS-Reference-TSconfig — pull request #2 by marble (2014-08-06 18:08:51+00:00)
Title: defaultLanguageFlag: you can use "multiple"

Use "multiple" to specify the multi-language flag. Concluded from the core source and tested and verified. You can't conclude this by watching gfx/flags/ as ther is no "multiple.gif" but only "multi-language.gif".