.dev/install/skel_basic/share/langs/README
Translations here. First level is locale name (ISO 2 letter), exactly like it is displayed in locale editor admin module.
Examples:
en/
register_en.php
my_translate_pack1_en.php
my_translate_pack2_en.php
ru/
register_ru.php
my_translate_pack1_ru.php
my_translate_pack2_ru.php