+1 I, too, need this feature! It should work just like a Unix symlink.
Just one example of why I need this (the one that prompted me to finally come search for it here):
I have collections for each class I teach. But often a topic is relevant to more than one class. For example, I was just adding an item to the "Price Controls" subcollection under my "Government and Business" class, but this subcollection also belongs under my "Principles of Microeconomics" class. As it stands, I either have to remember that this topic lives under the first class, or I have to create separate subcollections under each class and then copy every item over each time I add one.
Upgrade Storage
Just one example of why I need this (the one that prompted me to finally come search for it here):
I have collections for each class I teach. But often a topic is relevant to more than one class. For example, I was just adding an item to the "Price Controls" subcollection under my "Government and Business" class, but this subcollection also belongs under my "Principles of Microeconomics" class. As it stands, I either have to remember that this topic lives under the first class, or I have to create separate subcollections under each class and then copy every item over each time I add one.