I’ve just pushed an x32 image (i.e. platform linux/x32) which happily seems to work fine, except that it doesn’t come up with an architecture or OS category in the search:
(wryun/debian-x32-test is the repository in question)
What controls whether these categories exist?
I guess, but I am not sure that the architectures in the sidebar are architectures used by the official Images, verified publishers and OSS projects or the most popular architectures and pre-configured instead of detecting the available architectures automatically. If you feel an architecture is missing, you can report it on GitHub: