Once upon a midnight dreary,
while I surfed the web, weak and weary,
For pages long forgotten yore.
When I clicked my fav’rite href,
Suddenly there came a warning,
and my heart was filled with mourning,
Mourning for my dear /missing.pdf,
“Tis not possible!”, I muttered,
“Give thine pages, I implore!
Quoth the server: “404.”