They got merged together when I copied the data to BeerPal 2.0 when I made the current country list. That list came from the ISO 3166 standard for Country Codes. I use the ISO 3166-1 alpha-2 (wikipedia description) to save the country of each brewery in the database. It's also where I got the country flags that you see on the brewery profile pages.
It was kind of dumb to call Wales, Scotland, England, Northern Ireland all different countries because they're not. I found a lot of discrepenancies when I merged them back then. Officially it's the United Kingdom of Great Britain and Northern Ireland, or United Kingdom for short.