The TaxAct® programs select country codes according to the IRS Foreign Country Code Listing for Modernized e-File (MeF) webpage which is what software developers must follow.
As the IRS references that list for returns they process, only if they correct their listing for software developers can we change a code in our programs.
A current example is the code "BY" they show for "Burundi" while other sources reflect that as being for "Belarus" and the code "BI" being for "Burundi."
Note that any link in the information above is updated each year automatically and will take you to the most recent version of the document at the time it is accessed.