3.8 Property Names - definite article

The second list item under 3.8 Property Names reads in part:

*****
MUST be present in the JSON serialization of that resource.
*****

Should read:

MUST be present in the JSON serialization of a resource.

The rule applies to any resource and not some resource known at this point. It's a minor point but doing this consistently makes the document easier to read and interpret.