The Skype icon in the panel is an appindicator, so no, you cannot disallow it. The whitelist is for non-indicators, but since Skype uses an indicator, its allowed to come up there.
But this bug opens up a possibility: Should we add an indicator blacklist alongside the non-indicator whitelist? ** Changed in: unity Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/890231 Title: systray whitelist allows unlisted application To manage notifications about this bug go to: https://bugs.launchpad.net/unity/+bug/890231/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs