This is true. Also, they should send you a conformation email when you register and pay for proof of date. It usually takes about a year for you to get the official paper in the mail.
This link should answer most questions you have.
https://www.copyright.gov/circs/circ01.pdf
Do they still send paper? I dont recall getting a paper version last time...
I wonder if it can be printed off the site or something for older ones.? If it gets lost or didnt show up.
off topic, but I did make an error on one submission and the USGov wanted $135 to correct a title, even though the title was on the copyright in other places; the was missing in one line.
So I asked (emailed) "could it be edited?" etc...to fill a skipped/missed line.....they said "sure for $135!".
fyi...I recommend taking your time to fill the lines out and add notes in the comments etc..
As for timestamp, I agree with everyone else. You get the confirmation emails immediately so that seems to be the earliest date stamp (other than when the DAW hardrive could have the tracks labeled).
The last Ive done is CD full of tunes for my sons band and a couple singles of my own, just an old habit at this point, consider copyrighting part of the recording process for the price of a dinner out at $30-$35. For a whole CD of music its not a bad deal, doing a single it kind of sucks its the same price. So its like $35 for 28 songs or $35 for one song....seems kind of a ripoff ..er....or....a good deal depending on the quantity submitted.
I recall the old days it was a nice stamped paper, where the paper was actually braille like stamp you could feel, then it was changed to just photocopying flat stamps and now Im not sure what the forms look like, but hmmm? I dont recall even getting paper versions in the mail?