Crowner

Definition: The Lampshade Hanging of a Shout-Out. This means that an in-universe character recognizes the Shout-Out for what it is, and explicitly mentions the resemblance to other characters (or the audience). For example:

Character A: "Our Magic is not omnipotent... a little bit of courage is the real magic."
Character B: "Stop quoting Negima!"

Definition: Lampshade Hanging by means of a Shout-Out. That is, if a work is based on or inspired by some other work, it can acknowledge that (i.e. hanging a lampshade on its derivativeness) by adding one or more shout outs to the earlier work.

The definition is really pretty simple, and if you want the long version go look up Peter David's "But I Digress" Sept 20 1991 (which is where I took the idea, though not most of the samples, from).

The idea is that the creator is borrowing a chunk of a pre-existing work, but in such a way that it isn't directly obvious (not like say the Willy-Wonka episodes, which come out and scream it). If you are familiar with the older work he may be thinking "hey, this is a lot like X." The "slippers" are when the author slips in a specific detail (never a major plot point) that says "Yes I know this looks a bit like X, move along." The example David gave was some lifted dialog (and the slippers) when he realized one of his Hulk stories was tracking rather close to the movie Real Genius. Or Tim Burton naming the (non-super) Villain in Batman Returns after the star of Nosferatu "Yes, I'm doing all sorts of German-impressionist bits in this series, I know (and now you know that I know)". In The Dam Busters (one of the original examples) the moment is the lifted radio chatter (that didn't have to be copied word-for-word, but was.)

Sometimes, this sort of thing is retroactive (The Waynes seeing the "Mark of Zorro" on that fateful night is a classic retroactive one).

BGC doesn't really count, (the Blade Runner references are direct and obvious). A decent Anime example would be the one of the characters in Haruhi Suzumiya putting on Rosencrantz and Guildenstern are Dead for the school festival. "Yes this show is meta, I love meta and have seen every meta work you can name".

This is not when you have a Whole Plot Reference, rather when you borrowed a lot, but it got covered up. Some (but almost never all) of the audience will be thinking "hey that's from..", the slippers are when the creator says "Yes it is, now pay attention to my story" (said in a tone like Peter Faulk in the Princess Bride "Yes, you are very smart, now shut up."

I didn't fight megaphone hanging, because by that time there was a massive push to consolidate names (whether they worked or not) and it wasn't worth the fight. The trope has been there a LONG time (and got very nice reviews when it first got there), but it fairly narrow (with the massive increase of "examples" in the last few years, most of the older tropes have been stretched out of recognition).

Lampshades are when the characters point something out, usually in-story. This is the author speaking directly (but in code) to the audience, saying "Yes this looks like X, I am aware of it (and I might even have meant to do it), move along."

Definition: An "Inspiration Nod", where creators use a Shout-Out to acknowledge that an element of their work was specifically inspired by a similar element from a different work. The Shout-Out goes entirely unnoticed by in-universe characters and/or has no real effect on the plot; only audience members (sometimes, only those in on the reference) will even notice it's there at all.

Definition: a Shout-Out, but more subtle, i.e. one that only those familiar with the original work are likely to notice.