To the bottom-left of the Unearthly Horrors archive (and it is attached to Unearthly Horrors, since it remains at the same position when viewed on mobile and desktop), there is a small red-and-black file named Dagger.png that contains a dagger, along with the letters CND (this may have to be viewed in a separate tab).

This, of course, brings to mind the Cafe No Diner (the CND) and the Obscure Obelus Order (also known as the Daggers).

What should be noted is that the CND isn't just a random unimportant organisation as might be inferred from Open Doors; they're actually in possession of Dr. Crow's technology somehow and have a lot of hidden data unknown to the CaD.

Far more importantly to us, they also use their own CaDCom-style system known as the ZOTZ operating system. And, of course, it's the CaDComs (or equivalent) that allow people to write, and archive, receipts. Finally, taking the Unearthly Horrors page and adding a '-zotz' to the end of its URL gives us the Cafe No Diner webpage for Unearthly Horrors.