The three abbreviations below have something in common. A fourth abbreviation belongs in the list, but is given as a hint. Can you determine what these four abbreviations stand for and what they have in common?

1. NB
2. NL
3. NS

HINT:
The fourth abbreviation is PEI.

Answer:

The clues are abbreviations for Canada's four Atlantic Provinces:

1. New Brunswick
2. Newfoundland
3. Nova Scotia
4. Prince Edward Island