I think the convention for those capacity labels has changed, or some builders provide more info than others.
Lately, they provide an "empty" weight which I think is a unit with full oil and fuel but nothing else. And a disclaimer saying any dealer options will reduce capacity. Then some show capacities with given numbers of passengers. The most with just two, down to least with say six.
Reminds me of the ingredients of diet soda. They're required to print them, but they can choose a print style that discourages reading them. It's as if the coach companies don't want us to be able to compare across brands.