Error returned when a server cannot find the requested page.
Once upon a midnight dreary, while I websurfed, weak and weary,
Over many a strange and spurious website of 'hot chicks galore',
While I clicked my fav'rite bookmark, suddenly there came a warning,
And my heart was filled with mourning, mourning for my dear amour.
"'Tis not possible," I muttered, "give me back my cheap hardcore!"
Quoth the server, "404".
