This is your proof of posting. You can now use it to prove your existence to your cat, or to the DMV, or to the NSA. We can't really tell the difference, but it's fun to try.
Please note that this document is not actually valid for any real-world use. It's just for laughs, or for pretending to be a functioning society. If you're reading this, congratulations! You're part of the fun!
For more bureaucratic documents, try Assureance 13 or Assureance 11.