If there is an escaped name, autocompletion is not working properly. Say you have a network-device my-eth. If you run systemctl status and use the outcompletion, it will result in systemctl status sys-subsystem-net-devices-my\x2deth.device The outcompletion should use a \\ as one '\' is consumed by the shell or quote the argument.
Fixed in http://cgit.freedesktop.org/systemd/systemd/commit/?id=6d314eca15 (zsh) and http://cgit.freedesktop.org/systemd/systemd/commit/?id=c317a1a19c (bash).
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