Ebuilds do not list amd64 in keywords so I unable to install them. This files just plain text DTD files. Why to put dependency to platform? Better to allow such packages on any platform (for example Gentoo will be ported to another platform, and problem arise again).
just because it's only text that doesn't mean it works automatically on any arch. of course it is rather unlikely to cause problems, but you never know. i'm sure somebody will mark this soon.
But it is DTD (SGML), and it was designed to be platform independent.
Not all things that are designed to be platform independent actually are. This is part of our QA effort to ensure things marked ~amd64 or amd64 have *actually* been tested. I have tested these packages and I see no problems - therefore they are now marked ~amd64. This rule is Gentoo wide, and I happen to think it is a good one. There are a few Perl and Python apps that are supposed to be platform independent which are not. If you find stuff in future then please test it and file a bug requesting it to be marked ~amd64.
