Hello,
in the doc https://xlsform.org/en/#multiple-language-support , it is recommended to use the language codebook from Internet Assigned Numbers Authority (IANA) -
Using this recommendation, for instance here Spanish would then be label::Spanish (es) - but in the same page all over the document , we can see label::Español (es)
Which one is the best one? what the pros and cons for the different option?