San Marino is the smallest European country with its own national football league, the Campionato Sammarinese di Calcio.
The league was founded in 1985 and is organized by the San Marino Football Federation. Its clubs compete in a national championship, with the leading team progressing to UEFA qualifying competition under the relevant qualification system.
San Marino also has a national football team, but the league and the national team are separate institutions. The country's clubs play in the domestic competition, while the national side represents San Marino in international fixtures.
Vatican City is smaller, but it does not operate a comparable official national league within UEFA's club-competition structure. Monaco has a professional club, AS Monaco, which plays in France's football league system rather than a separate Monegasque national league. These distinctions make the wording important.