Sometimes you want to add notes to a node without making it permanently part of that node. We call this contextual content, and it's available as columns in the table view and on items in the list view. This is great for:
Christmas present planning. You may want to reuse a list generated from a #person supertag, but you don’t want your gifting ideas made permanent in those people’s entries.
Status notes. Making contextual nodes on a "Done" or "In waiting" status of a task to disclose nuance.
A vacation schedule. You don't want May and June to be part of the node Alex Strikha, showing every time you click the node. You just want it in this context:
Contextual content tends to be most helpful when you write a live search (viewed as a table) and want to process all of the results in some way without adding new data directly to the nodes. It can be as simple as adding a contextual checkbox field that says "I already looked at this."
If I reference "The Four Steps to an Epiphany" in another location and expand the reference, I won't see the "Processed" field on it, because that field is only on the reference in the context of "Reading list for today."
A reference with contextual content will display as a diamond instead of a circle.