All i18n (internationalization) file (*.po) master copies are stored as sub-pages of this page. See MoinDev/Translation for details.
The wiki engine currently does not directly use the content of these pages, but the data on those pages will be used by the build process to generate MoinMoin/i18n/*.po files.
List of i18n pages:
If you get a status saying that there are a few untranslated messages, just search for !!!!, remember the english text from the msgid above it, click on edit, search for that english text (use your web browser's in-page search function), fix it and save it again. Repeat until all is translated.
If there are lots of untranslated messages, just review it from begin to end.
The translations marked with -FIXME are orphaned and didn't get updated recently. If they go below some ratio of translated/total strings, they get removed due to quality considerations. You can help reviving them by fixing what's wrong and translating what's missing, so they can get included again.
Translations done by directly committing to arch (i.e. not here):
he (hebrew) - send comments and patches to NirSoffer