I would like to ask a question about Newfoundland, and noticed there's no specific tag for it. Given how this conversation turned, I figured I'd make it more of a general case so we don't have to re-discuss this for other countries that are in a similar situation.
With regards to Newfoundland, it was an independent Dominion (though home rule was suspended in 1933) before it joined Canada in 1949.
As a comparison:
The other Canadian provinces with the exception of quebec do not have one;
None of the Australian states/territories have a tag;
Of American states, california, vermont, new-york, washington-state, texas, florida, missouri, west-coast, new-mexico, hawaii, alaska—I think I tried all US states' now but might have missed some;
I don't think any Brazilian, Indian, German, Austrian, or Mexican states have a separate tag (though I didn't verify these separately) with the exception of bavaria.