template property

The locale the source text is written in.

It decides two of the three findings an export can make, which is why it is declared rather than assumed: a key the template has no text for is skipped entirely — there is nothing to fall back to, and a key only a target locale defines is usually stale — and a locale that is the template is never reported as falling back to itself or as disagreeing with itself. It is also the text shown beside a key as what a translator is working from.