See for example the translators interface on Facebook that allows adding optional variants based on explicit conditions; but where all of them remain optional with a common fallback to the default form.

2014-10-29 10:21 GMT+01:00 Niklas Laxström <niklas.laxstrom@gmail.com>:

2014-10-29 10:58 GMT+02:00 Philippe Verdy <verdy_p@wanadoo.fr>:
> I'd then suggest that the trnaslation interface allows selecting BOTH the number and grammatial case to map them to one of the possible forms, and then let the adapter interface mame the necessary mapping to the precise symbolic forms or one of its fallbacks.

I18n and l10n is complex topic. We are trying to keep it as simple as
possible for translators and developers. What you propose does not
bring more power to the system, only makes it more complex.

-Niklas