Where can I find a list of language + region codes?

Question

I have googled (well, DuckDuckGo\'ed, actually) till I\'m blue in the face, but cannot find a list of language codes of the type en-GB or fr-CA any

Answer 1

List of primary language subtags, with common region subtags for each language (based on population of language speakers in each region):

https://www.unicode.org/cldr/charts/latest/supplemental/language_territory_information.html

For example, for English:

• en-US (320,000,000)
• en-IN (250,000,000)
• en-NG (110,000,000)
• en-PK (100,000,000)
• en-PH (68,000,000)
• en-GB (64,000,000)

_{(Jukka K. Korpela and tigrish give good explanations for why any combination of language + region code is valid, but it might be helpful to have a list of codes most likely to be in actual use. s-f's link has such useful information sorted by region, so it might also be helpful to have this information sorted by language.)}