Comment by danabramov

You can indeed backdate records. Since the application knows when it has first seen (i.e. indexed) your record, it can decide what to do with that information. If there's a difference, the Bluesky app, for example, shows its own indexing time, but also shows a separate panel saying the post is backdated to some other date. Other apps could choose to show something else.

It is possible to create links asserting a specific version by making a "strong ref" which includes content hash.