Check it: the colon is coming back into vogue, with a twist.
For grammarians, it’s a dependent clause + colon + just about anything, incorporating any and all elements of the other four colons, yet differing crucially in that its pre-colon segment is always a dependent clause.
For everyone else: its usefulness lies in that it lifts you up and into a sentence you never thought you’d be reading by giving you a compact little nugget of information prior to the colon and leaving you on the hook for whatever comes thereafter, often rambling on until the reader has exhausted his/her theoretical lung capacity and can continue to read no longer.
Comments? I don’t do open comments. Life is too short.