CodeSystem Supplement Properties for Unaccounted for Languages

I have languages that are not accounted for by the FHIR value sets for codes like the language Afrikaans. I have seen through FHIR documentation that I can use CodeSystem Supplements to compensate for this but I have not been able to determine what exactly the code should be. I have only seen one example (Codesystem-example-supplement - FHIR v4.6.0) and it is still not clear how I should apply it to my own use case while still adhering to FHIR protocols. Could I be offered another example and more guidance on making these CodeSystem Supplements?

With a CodeSystem supplement, you use the same codes as the original code system, and simply provide additional designations or properties. You can certainly submit a change request asking for more examples in the core spec.