Element can match multiple ifs under Element Click

In chapter 14. Element Interaction, section 14.1 Element Click:

If the element’s center point is obscured by another element, an element click intercepted error is returned. If the element is outside the viewport, an element not interactable error is returned.

An element outside the viewport is obscured, therefore given there's nothing saying that you do these in order (indeed, it makes no sense to apply these sentences after the previous one!), so it's ambiguous as to what error should be returned.

Start with section 14.1, Element Click, in the linked WebDriver specification and read the surrounding interaction-error text. Determine how the obscured and out-of-viewport conditions should be ordered or distinguished, then update the normative wording so one unambiguous error is selected and review the resulting specification text.