Old fashion notaries hate this option to time stamp and register a document, because is destroying their monopoly. But I found some that are using this tool too, because they want to reduce their papers in storage. So an opentimestamp register is easy and can be verifiable until end of times by anybody.

Also some notaries do not want to register any kind of document... so your best option is blockchain time stamp.

I think you can put anything meaningful there 👀 yet people are doing the dump jpeg...

Like I would had timestamp the day I quit! one of the best decisions I had made in my life.