Possibility to reuse the list of languages available for "Preferred language"
Out of the box, CiviCRM comes with a full list of languages used for the field "Preferred language". Right now, there is no way to reuse this list in custom fields. Admins must create their own list of languages manually or use different unsupported approaches to reuse the one CiviCRM already has.
An international organization working with volunteers wants to know in which languages they have basic, advanced, and native/professional fluency, in separate questions.
The list of languages available in CiviCRM's database cannot be reused for custom fields.
Make the "Preferred language" list of languages available to custom fields, just like you can create any list that is then available to other custom fields.
See examples of ad hoc solutions admins are recurring to on https://civicrm.stackexchange.com/questions/6604/how-to-reuse-preferred-language-select