It’s not listed here either 🙂 : http://genericons.com
So it’s a secret one 😉
Bit of a late reply, but not sure if you mean it is genuinely a secret one, or you’re just joking around. 😉
Here’s two screengrabs to show what I mean. First, the the dashboard page for Genricon’d on my website…
http://imgur.com/p3Enci0
If I then click on the link called “the official Genericons Examples”, circled red on the image above, it takes me to the page which is on the screengrab below…
http://imgur.com/79ZW7Ox
On that page, there is a “404” icon, 5th row down, 1st icon. So is that not part of Genericons any more?
No, not joking! It’s an easter egg.
Look here: http://genericons.com/
See how it’s NOT on that page? That’s why it’s NOT on the default page in the plugin either. It’s a secret/hidden surprise. Yes, it’s included. Yes, it’s a part of Genericons and Genericon’d. No, it doesn’t display on purpose. Yes, you can use it if you know about it.
Hence … Easter Egg 🙂