Binary package “locales” in ubuntu xenial

GNU C Library: National Language (locale) data [support]

 Machine-readable data files, shared objects and programs used by the
 C library for localization (l10n) and internationalization (i18n) support.
 .
 This package contains tools to generate locale definitions from source
 files (included in this package). It allows you to customize which
 definitions actually get generated. This is a space-saver over how this
 package used to be, with all locales generated by default. This created
 a package that unpacked to an excess of 30 megs.