Link receipts together to show when one receipt supersedes another

[RichardGomer]

Is your feature request related to a problem? Please describe. One quality of consent is that it must be mutable - i.e. it can change. At present, there's no way to indicate if a consent receipt supersedes a previous one, which will make it difficult for wallets etc. to accurately determine the current state of an individuals' consent based just on the receipt trail.

Describe the solution you'd like There should be a way for a receipt to indicate which receipt(s) it supercedes. If each receipt was given a unique ID of some kind (e.g. a GUID plus issuing domain) then later receipts could indicate which receipt(s) they supercede in a new field.

This would effectively build up a linked-list of receipts, showing how consent has changed over time. Ideally, receipts would list more than just the last one in the chain, so that if a single receipt goes missing the chains don't become broken. It's probably feasible, in most cases, to list ALL of the prior receipts.

Describe alternatives you've considered

Additional context This imposes some additional semantics on the receipt; what if Q supercedes P but doesn't contain all of the same purposes? Are those purposes revoked or just left 'as-is'? I will file another issue for the latter.

[JamesOTL]

I support Richard's proposal.

[crtahlin]

I support the general reference idea. But, in our specific case & the context of blockchain, we are using different identifiers for tracking the chain of consents.