"This is the third stage of India's PSLV rocket."

There should be regulation that requires such objects to be properly labeled.

They ARE labeled, but they don't exactly come back down in a controlled fashion where the labels necessarily survive.

And even if it the label survived, its not like a bunch of part numbers would mean anything at all to a lay person and would still generate these dumb posts.

Meanwhile integrating sufficient labeling to the manufacturing and testing process costs time and money in perpetuity.

Half of it is probably burned up

If you zoom in on some of the pictures you can see what looks like partial labels, maybe part or serial numbers? But all of them are pretty burned and chewed up. And based on the barnacles, it spent a lot of time at sea too before washing up.

That's pretty typical. SpaceX debris that washes up in the Caribbean is in similar condition.

Hah, I love stuff like this, but part of me wishes it had taking just a bit longer to figure it out. I really enjoy the mystery.