Ok.. seems minor, but it has puzzled me for a long time. We do server changes at work via a set of files some of which add registry entries. And we are supposed to have a set of “roll back” files that will undo what we did. For the longest time, we did not know how to delete a registry value via a .reg file. And so had manual instruction on how to delete it manually. well, today, I just happen to do a search on Google and found out:

[HKEY_CURRENT_USER\DummyTree]
“ValueToBeRemoved”=-
source: www.robvanderwoude.com/regedit.html