There are a number of widely used directories with no clear natural owner, that should probably go into filesystem (or in the future, in a filesystem-desktop subpackage): /usr/share/themes - natural companion to /usr/share/icons, which is already there /usr/share/backgrounds - for this one, we could alternatively declare desktop-backgrounds-basic to be the official owner... /usr/share/gtk-doc/html - since /usr/share/gtk-doc is already there, and the html subdirectory is the actually problematic one. Although I must admit that I'd be just as happy to have these be owned by gtk-doc
/etc/fonts/conf.d needs to join them. Our font packaging guidelines ask for font packages not to depend on fontconfig. However several packages drop fontconfig rules in /etc/fonts/conf.d (the rules are interpreted if fontconfig is present. If not the main "feature" of font packages, the font files themselves, is still available for use, and the rule files harm no one) Currently that means /etc/fonts/conf.d can be used without a package owning it. To respect the "directory ownership" guideline this directory should be transferred from fontconfig to a neutral filesystem package font packages can depend on (without forcing install of fontconfig binaries)
I agree with /usr/share/themes and /etc/fonts/conf.d being part of filesystems, changes have already been put it. For /usr/share/backgrounds and /usr/share/gtk-doc/html i'd rather seem those being owned by the packages you mentioned above. Fixes will be in next filesystem build. Thanks, Read ya, Phil