Scope="rowgroup" on a single row

In the solution to planets data assessment, “Dwarf planets” header has a scope=rowgroup although it contains a single row. I understand it is a container for another header (Pluto) but shouldn’t it be scope=row instead? According to the tutorial colgroup / rowgroup should

sit over the top of multiple columns or rows

@aviv.mu Yup, I think you’re right. I’ve updated the example and the marking guide to suit.