Example 22 uses termsOfUse

[pchampin]

Example 22 uses termsOfUse as a property of a veriable presentation.

However, in the context, termsOfUse is only defined in the local context of VerifiableCredential.

[wyc]

Thanks @pchampin for spotting this errata. There appears to be two ways about this.

1. Change example 22 by removing use of termsOfUse
2. Add termsOfUse to the VerifiablePresentation context definition

Do you have a preference? The first change is not likely to be considered substantive, whereas the second one may be.

cc @msporny for any thoughts on the substantiveness of modifying the VP context defn

[msporny]

Example 22 uses termsOfUse as a property of a veriable presentation.

However, in the context, termsOfUse is only defined in the local context of VerifiableCredential.

Yes, this is a bug in the JSON-LD context, nice catch @pchampin!

Noting what the spec says for ToU:

"Terms of use can be utilized by an issuer or a holder to communicate the terms under which a verifiable credential or verifiable presentation was issued."

We always meant termsOfUse to be usable from within a presentation... we just didn't carry that through to the JSON-LD Context.

cc @msporny for any thoughts on the substantiveness of modifying the VP context defn

Imma spec language lawyer here for a second:

1. We always meant termsOfUse to be usable from within a presentation.
2. The JSON-LD Context in the specification is non-normative.

So, technically speaking, we could update the JSON-LD Context in place and fix the bug per W3C Process.

takes spec lawyer hat off

That said, I don't think we should change the 2018 VC context and fix it... people are using that context in production. We should treat this like a substantive change and put it in the next JSON-LD Context for VCs. I suggest that even though it's not a "W3C Process defined substantive change" to the 2018 context, it's still effectively a substantive change since it would affect implementation behavior (the term would go from being dropped to not being dropped during signing).

Instead, we should fix this in the next version of the VC context... noting that we're going to be making a bunch of other changes at the same time (like factoring the cryptosuites out). This is good, this is why we set up JSON-LD Contexts to work this way... at this point, implementers have multiple choices:

1. Add termsOfUse to their own context for presentations if they really need it.
2. Wait for the VC context to be updated.
3. Don't be forced to break backwards compatability.

We probably just need to go with @wyc's first suggestion, remove ToS from the example for now, which makes me sad.

We should then immediately add it back in for v2.0 and define it properly.

[kdenhartog]

I've written a PR to remove this from the specification per @wyc option 1. We'll need to either update this issue afterwards and leave it open to track re-adding the text back in or we'll need to open another issue after it's been merged.

[kdenhartog]

addressed in #787

closing.

[TallTed]

@kdenhartog -- Since this is closed, please add a link here or there connecting this issue to the new one about putting the text back in. The new issue should be tagged for version 2.0, if it isn't already.

[kdenhartog]

Thanks for the reminder @TallTed. I've gone and created a follow up issue to address this in V2 in #810