A "closed-door tour" (okružní jízda) is considered to be:

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International occasional transport of persons on order along a pre-reserved circular route, where the same group of passengers is transported by the same vehicle.

Transport of persons on a passenger transport line through cities and municipalities, where the starting and ending place of the journey is the same.
A trip with a travel agency with a sightseeing destination.

Closed Group: This defines a specific type of international bus transport (Interbus agreement).

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