Comment:

"locations are always reported using a simplified XPath notation" - not true. They can also be reported by expression. We need guidance on when to use location vs. expression and indicate what systems can count on. Two ways to solve the same problem isn't good. And if JSONPath standardizes we could end up with 3 ways. Can't we just provide algorithms to convert from expression to XPath or JSONPath and back?

Summary:

location + expression is a problem