CEX (Webuy.com) game descriptions "S", "SN", "Offline" etc

If you go to
uk.webuy.com/sea…ons
It shows the same game listed twice.

Does:
"(S)" mean "Sealed"?
"Offline" mean you probably can't use the offlinefeatures as the serial number will probably have been already used?
"(SN)" mean (not sealed but) includes serial number for installation?

Are there any more abbreviations I might come across?
I did look around their help pages but couldn't see it.
Many thanks in advance.