<p><a target="_blank" href="https://go.cpanel.net/localedocs">Cpanel::Locale</a> uses proper ISO codes that have data defined in the CLDR.</p>
<p>The legacy language system used any arbitrary naming you wanted. When bringing legacy files into the locale databases an attempt is made to determine what standard ISO code would best suit the legacy name.</p>
<p>If the ISO code it belongs to can not be determined automatically then it will be created as an "i_" notation code. For example "l33t speak" does not have an ISO code so a legacy file called "l33t.speak" would be referred to as 'i_l33t_speak' in the locale system. </p>