There isn't really an official stance. It's neither explicitly allowed nor denied. Feel free to add the architecture if the package works on a specific ARM architecture if you want.
There is an official stance as dictated on the wiki [1] however I happen to agree with the last part of what you said. Strictly speaking, maintainers shouldn't add anything except i686, x86_64 or any. That said, I don't see why anyone short of being truely anal would request that, say, an armv6h architecture entry be removed from a PKGBUILD if it also already specifies i686 and x86_64. i686-x86_64-any anal-ness belongs in the official repos, the forum and to a large extent, the wiki. [1] https://wiki.archlinux.org/index.php/Arch_Packaging_Standards#Architectures -- David Phillips GPG Key 0x7BF3D17D0884BF5B Fingerprint 2426 235A 7831 AA2F 56AF 4BC0 7BF3 D17D 0884 BF5B