I sometimes use a no-op action ‘quote’ (a link to this node) to indicate that the block in question is a quote lifted from somewhere else — often [[wikipedia]] or the link the block is a child of.
I do this because Markdown’s quote operator (>) does not play well in lists (which I use to represent blocks in the [[agora]]).
A nice side effect is that you can see backlinks in this node to find quotes around the [[agora]].