For example, for the like UI for XWIKI-18545, we have the following translation (in french):

like.likers.link.zero={0} J''aime

(the doubled single quote is needed because it's a parametrized message and this is the format for such messages).

When used from velocity, it displays as "0 J'aime" (correctly), when fetched from javascript using the xwiki-l10n API added by XWIKI-18973, it shows "0 J''aime" (incorrectly).