Currently for gregorian we have the following in "root":
and we have the following in "en", for example:
We need a way that locales can provide data for an alternate secular/neutral era name if their default era name has a religious basis (as with the current en/gregorian/era naming).
Since many locales already use a secular/neutral name as the default for gregorian, this would need to fall back to the default name in the same locale.
The easiest way to do this is just provide <eras alt="variant">l in locales that need it. A request for the "variant" form will fall back to the default form in the same locale if no "variant" form is present. So in "en" we would add this:
(We could use other names for the alt form such as "secular" or "neutral" but "variant" is more general and already widely supported.)