imagemagick: preferred and deprecated versions
Preferred and deprecated versions can be used to influence Cabal's decisions about which versions of imagemagick to install. If a range of versions is preferred, it means that the installer won't install a non-preferred package version unless it is explicitly specified or if it's the only choice the installer has. Deprecating a version adds a range which excludes just that version. All of this information is collected in the preferred-versions file that's included in the index tarball. [maintainers: edit]
If all the available versions of a package are non-preferred or deprecated, cabal-install will treat this the same as if none of them are. This feature doesn't affect whether or not to install a package, only for selecting versions after a given package has decided to be installed. Entire-package deprecation is also available, but it's separate from preferred versions.
Preferred versions for imagemagick:
Explicitly deprecated versions for imagemagick include: 0.0.1, 0.0.2, 0.0.3, 0.0.3.1, 0.0.3.3, 0.0.3.5The version range given to this package, therefore, is >0.0.2 && <0.0.3 || >0.0.3 && <0.0.3.1 || >0.0.3.1 && <0.0.3.3 || >0.0.3.3 && <0.0.3.5 || >0.0.3.5
Blue versions are normal versions. Green are those out of any preferred version ranges. Gray are deprecated.