https://www.drupal.org/node/882164
Adding a language help page during installation is incorrect [#882164] | Drupal.org
Mar 13, 2015 - This might not be a bug but my own stupidity, but it seems strange and I need to report. I would like to add a language during installation. These are the...
adding a languagehelp page
https://developers.whmcs.com/languages/adding-a-language/
Adding a Language - WHMCS Developer Documentation
WHMCS developer documentation - themes, modules, hooks, oauth, api and more...
adding a languagewhmcsdeveloperdocumentation