Which standard is that? ePubs, for example, use canonical fragment identifiers, which could also work on HTML. I think hypothes.is uses them too but adds fuzzy matching fields so that they can match up after document changes. At least from what I remember
I'm working on an annotation project myself, though not really related to what the parent commenter is looking for. A generic solution to the highlight/annotation problem is quite difficult, especially if you allow for document changes.
I read through the docs when they first came out but I don't remember all of the details anymore. Fragment identifiers are part of it though. I've gone back and forth on how much I like them, allowing for document changes is always going to make stuff really complicated, fuzzy/fragment matching is about the best you can do I think without the cooperation of the source you're annotating.
It feels like annotations probably should be tied to specific document versions, but I also get the reasoning why they're not in this proposal. Unless you're self-hosting everything or forcing everything to go through the Internet Archive... it's just kind of difficult.
I've been curious about trying to get annotations to work before using something like Matrix to handle accounts/groups, but not curious enough to actually try to build a working example.
I'm working on an annotation project myself, though not really related to what the parent commenter is looking for. A generic solution to the highlight/annotation problem is quite difficult, especially if you allow for document changes.