Is there a best practice for internationalizing large amounts of text for built-in theme documentation or similar other than just wrapping in the __() or _e() functions?
Maybe providing ways of including different txt files based on language settings? (en_EN-setup-info.txt, bg_BG-setup-info.txt,, es_ES-setup-info.txt, etc…)
I suggest sticking to _() or _e() as in WordPress 3.3 they are adding language packs for core/plugins/and themes ….. I haven’t had time to dig into what it will actually do and theres not much docs on it yet
check also CodeStyling plugin,http://wordpress.org/extend/plugins/codestyling-localization/
we recommend it to our theme buyers… it also has built-in scanner to update the translation file.