For those of you wondering why they got a 404 when clicking on the link contained in the mail sent out by the mailing list software: Thanks to Mailman :-) the terminating dot was included in the link determination algorithm resulting of course in a wrong URI.
Here's the correct one (now with extra spaces): https://monochromec.com/Arch_DevRoom_CfP.html . :-))
arch-events@lists.archlinux.org