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Please note that unless you use a very old LabVIEW version, there is actually no need to put the Close Reference node into a loop. It perfectly will accept an array of refnums too. As to worrying about if a Close Reference node is necessary or not during a code review, tell the reviewer that there are more important things to worry. 😃 If that are the only things he can complain about, he is either worthless as a code reviewer or your code is prime quality. 😀 For ActiveX (and .Net) refnums it absolutely and positively is important to avoid potentially huge memory hogs (not really memory leaks as LabVIEW still knows about the objects, they just never get disposed until you terminate your application). One of the VI reference close functions marked as questionable also is needed, the other not! ActiveX and .Net objects are refcounted and will often prevent not just themselves to be deallocated but also parent objects, depending if the child object has somehow acquired a reference to the parent for some reason. Any such object wanting to retain access to another object is required to obtain a reference to it which will increase the refcount and only once each reference to an object has been properly closed, will the object actually be released. LabVIEW as simply being another client of the ActiveX or .Net object needs to follow that rule too, so if you don't close the LabVIEW refnum, it won't release the underlying reference to the object and any objects that this object has referenced will also stay in memory. So rather than erring on the wrong side I prefer to err on the good side and simply put a Close Reference anywhere without even spending a Joule of energy to reason if it is really needed. That little extra muscle exercise in the fingers is not that bad. A Close Reference on a refnum that does not need to be closed is simply a NOP (No Operation) in LabVIEW (well factually it is checking a dynamic attribute of the refnum and skipping any attempt to close the refnum if it doesn't need to but that check is about as expensive as your "Not A Number, Path, Refnum" node). So from all the marked Close functions the ones being marked OK are indeed needed. From all the others only one can be definitely deleted (the array of control refnums obtained by the Control Reference Constants) . All the ActiveX closes are definitely needed and the refnum returned from the Controls[] property of the Cluster refnum might be maybe not required. But I wouldn't want to go and spend any energy to find out about that so I would leave it in, which would only make one Close being clearly useless (the uppermost).