In regions that have multiple official languages, transit agencies/operators typically have language-specific names and web pages. In order to best serve riders in those regions, it is useful for the GTFS feed to include these language-dependent values.
Hello
The current version of the feed validator does not support the translations.txt file. This file is part of the extensions to GTFS, here: https://support.google.com/transitpartners/answer/2450962
Regards