[edwintorok]

What happens to other URLs embedded in the document that you link to with trusty URLs (other than self-references?). For example your document could include images, and javascript that could completely the meaning of the document, while keeping the hash of the document the same.

Do you require all URLs contained in the document to be trusty URIs too?

[tkuhn]

No, there can be contained URIs that are not trusty (probably the majority of contained URIs will be of that type). You can verify the entire reference tree as long as you follow trusty links, but of course this cannot go on indefinitely. Furthermore not all resources have the form of what I call a "digital artifact" (e.g. foaf:knows does not stand for a digital artifact), but they reach out to the real world (these URIs might not even return a representation, i.e. they might not be URLs).