You can download and use the items in this Register from the terminal by using the Registers.app command-line tools.
Get a copy of the orc tool by following the instructions on GitHub.
Save a live copy of this Register:
$ curl https://registers.app/register/11:70/rsf | orc clone - country
Use orc to use the data from the Register and keep it up to date:
$ orc ls country user
You can read more about how to use the command-line tool on GitHub.
You can use the items in this Register as options on a form in your own service. The picker will pull the latest version of the records and keep itself up-to-date.
Select a human-readable field to use as the text in the picker.
Your new picker will look like this:
Embed this code where you'd like the picker to appear.
Use the items in this Register to make a drop-down autocomplete menu.
Connect the orc command-line tool and use this Register from the command line.
British English names and descriptive terms for countries as recognised by the UK government
David de Silva