'archives' contains artifacts from other configurations

Gradle Version: 2.13
Operating System: OSX
Is this a regression? unknown

I have noticed that ‘configurations.archives’ contains artifacts for things that were never added to that configuration. This seems like a bug. There is no way to make an artifact in a different configuration that depends on artifacts from the ‘archives’ configuration. Yet, many things are only added to the ‘archives’ configuration, such as all the java artifacts.

If ‘archives’ is supposed to be some sort of magic ‘catch all’ configuration to which all artifacts are automatically added, it seems that manually adding things to this configuration should be forbidden, so that the artifacts exists in at least one other configuration separate from all the artifacts.