When a series format is copied in countries other than the series' original country (e.g. The Voice, Love Island, etc.), the Series Name of any series other than the original should follow the following rules re: appending country name/abbreviation to the title: 

Let's take Love Island for example. 

• The series format originated in the UK — since it's the original version of this format, the title doesn't need a country appended to it. It should simply be titled Love Island.
• The format was also moved to Australia, where the official series title is Love Island Australia. In this instance, the title should be Love Island Australia.
• Alternatively, the title of the same series format in the United States is simply Love Island. In this case, we should use the country designation in parentheses after the title — Love Island (US) — to differentiate it from the original UK version of the series.