@ubx @pluralistic

I'm picturing rooms full of Dickensian clerks manually doing the computations to verify the block chain transactions without power.

@chrysn @jyasskin indeed, “memento” points from an original resource to a snapshot thereof, whereas “original” points from a snapshot of a resource the original. In Tim BL’s terminology, the original resource is a “time generic” resource https://www.w3.org/DesignIssues/Generic.html

@chrysn @jyasskin This RFC contains a nice analysis of the actual meaning of relation types like “alternate”, “bookmark”, “duplicate”, … https://www.rfc-editor.org/rfc/rfc8574.txt

@jyasskin A date in data-versionurl is the snapshot date of the URL of the version resource that precedes it in the list. That’s e.g. the URL of a resource in web archive A. In case that URL is no longer accessible in web archive A (result of takedown request, for example), then the date can be […]

@jyasskin that’s part of the memento protocol. It’s datetime content negotiation. That can also work for datetime access to resources in eg wikis, btw. But, thus far, mainly web archives have implemented support.

@jyasskin Note that the datetime annotations are rather relevant when interacting with web archives, most of which support the Memento “Time Travel for the Web” protocol https://www.rfc-editor.org/rfc/rfc7089.html

@jyasskin Regarding (1), see Robust Links https://robustlinks.org/spec/