Publisher applies a translation based on the user's selected Report Locale.
Publisher first tries to match an RTF template named for the locale, then an XLIFF file named for the locale. If an exact match on language-territory isn't found, then Publisher tries to match on language only.
For example, if you have a report for which the base template is called EmployeeTemplate.rtf and the locale selected is French (France), then Publisher selects the translation to apply according to the following hierarchy:
With the same set of translations, if the locale selected is French (Switzerland), then the EmployeeTemplate.rtf (fr) is applied. Now if the available translations are limited to the following set:
and the locale selected is French (Switzerland), then the EmployeeTemplate.rtf (default) is applied. Even though there's a language match, Publisher doesn't match the different locales.
Therefore, to ensure that a French language translation is used when French is the selected language, regardless of the selected locale, you must include either an rtf or xlf file named for the language only (that is, EmployeeTemplate_fr.rtf or EmployeeTemplate_fr.xlf).