If you filter the alternateNames by isolanguage with e.g. en and eng (or zh and zho) you´ll notice that they´re both in the list. en-entries are the major but there are even some eng-entries. That can´t be intended?!
You may should change the column name to Alpha3 or something and it would became clearer.
ps: i haven´t checked whether the data is matching...
Thanks , I have converted all 3 letters code two their 2 letter code if it is available and will implement a conversion in the user interface when users add new translations.