The clerk pointed to a small plaque on the wall—the . It listed the only "verbs" the building accepted: GET, HEAD, OPTIONS .
"I’d like to this letter into the library's collection," Eli said, sliding a sealed envelope toward the slot. 405 Not Allowed
"The library is right here," the clerk droned, pointing to the shelves of books behind him. "You’ve got the right place. But this is an . It is a read-only establishment. You can GET a book, you can HEAD a title, but you cannot POST a letter here. We simply don't allow that method of interaction." "But I have to leave this letter!" Eli insisted. The clerk pointed to a small plaque on the wall—the
"I don't understand," Eli said. "Is the library closed? Is the address wrong?" "The library is right here," the clerk droned,
In the bustling city of Silicon Circuit, every citizen is a and every building is a Server .
Eli sighed, realizing his mistake. He had the right address, but he was trying to use an "enter" key on a door that only had a handle to "exit." He tucked his letter away and set off for the correct endpoint.