The element that serves as the container for the set of tabs has role tablist.
Each element that serves as a tab has role tab and is contained within the element with role tablist.
Each element that contains the content panel for a tab has role tabpanel.
If the tab list has a visible label, the element with role tablist has aria-labelledby set to a value that refers to the labelling element. Otherwise, the tablist element has a label provided by aria-label.
Each element with role tab has the property aria-controls referring to its associated tabpanel element.
The active tab element has the state aria-selected set to true and all other tab elements have it set to false.
Each element with role tabpanel has the property aria-labelledby referring to its associated tab element.
If a tab element has a pop-up menu, it has the property aria-haspopup set to either menu or true.
If the tablist element is vertically oriented, it has the property aria-orientation set to vertical. The default value of aria-orientation for a tablist element is horizontal.
When focus moves into the tab list, focus is placed on the active tab element. When the tab list contains the focus, focus moves to the next element in the page tab sequence outside the tablist, which is typically either the first focusable element inside the tab panel or the tab panel itself.
