Current spec
Source code

Assume the ideal case, where that the server has responded with Content-Type: application/ld+json:

• We skip step 4, since we have the +json suffix
• We skip step 5, since application/ld+json is specifically excluded
• Then, we reach step 6

Currently this is worded as:

"Otherwise, the retrieved document's Content-Type is neither application/json, application/ld+json, nor any other media type using a +json suffix as defined in [RFC6839]. Reject the promise passing a loading document failed error."

I think this is a mistake, and it should read as follows, because of course we do have application/ld+json:

"Otherwise, if the retrieved document's Content-Type is neither application/json, application/ld+json, nor any other media type using a +json suffix as defined in [RFC6839], reject the promise passing a loading document failed error."

This is almost certainly a mistake because step 7 proceeds with the algorithm, even though the current wording of step 6 implies that it will always fail here.

Happy to put in a PR here.