Refreshing how far RC managed to take me without my even realising that I was learning something! Tiniest of nits: conflates lossless and lossy compression with the ZIP example.
If you wish to refer to the submission uniquely in the subject, as of a few years ago anyways they requested appending ` (1235676423)` to the end of it with the ?id=1235676423 of the comment/post/whatever that you're writing about. I tend to do so more in emails sent from a keyboard than from a mobile phone for UI reasons.