Language code and country ID - conventions on language filenames

English Language - Forum Translation and Language Packs
1

What should be the preferable way to state a language ID? Should we use the capital letters?
SUITECRM use only lowercase for filenames.
But the standard use is:
lower case letters to indicate language (ISO 639) followed by underscore followed by upper case letters to indicate the country code (from ISO 3166).

See:
ISO 639-1 defines two-letter language codes for many languages - http://en.wikipedia.org/wiki/List_of_ISO_639-1_codes
ISO 3166-1 defines two-letter country - http://en.wikipedia.org/wiki/ISO_3166-1_alpha-2

So this would be an example for the config file for pt-PT Portuguese (Portugal) language:

    'id'=> 'pt_PT',
    'lang_file_suffix' => 'pt_PT',

and language files as:
pt_PT.AdvancedOpenSales.php

or should we use:

    'id'=> 'pt_pt',
    'lang_file_suffix' => 'pt_pt',

and language files as:
pt_pt.AdvancedOpenSales.php

2

In my opinion you should follow the SugarCRM language convention keys

So in your case pt_PT

The Dutch Language pack contains file with the following convention: nl_NL

3

Thanks! That was also my initial option.

The question has been posted because the SuitCRM download pack includes languages in small caps
Spanish = es_es (not es_ES as in the convention link)
English = en_us
Russian = ru_ru