While I agree that XML has muddy-thinking whether tags are types within a collection or properties of an object, I've often felt that Json's inability to store

While I agree that XML has muddy-thinking whether tags are types within a collection or properties of an object, I've often felt that Json's inability to store heterogeneous object arrays meaningfully is a big problem. The lack of a meaningful "type" attribute in JSON schema is a pain. I've had to roll my own hack for such cases.