CORE/_mcl_autogroup/init.lua:
-> Enumerates entries of the registered_nodes table.  Safe.

CORE/flowlib/init.lua:
-> All instances are checked before use.

CORE/mcl_explosions/init.lua:
-> Enumerates entries of the registered_nodes table.  Safe.

CORE/walkover/init.lua:
-> Enumerates entries of the registered_nodes table.  Safe.

CORE/mcl_util/init.lua:
-> All instances are checked before use.
- should use local.
- defines mcl_util.call_on_rightclick, but does not use it.