Via Slash Gear
 
 
 
 
 
 
 
 
Everyone on the internet
 has come across at least couple error codes, the most well-known being 
404, for page not found, while other common ones include 500, for 
internal server error, or 403, for a "forbidden" page. However, with 
latter, there's the growing issue of why a certain webpage has become 
forbidden, or who made it so. In an effort to address things like 
censorship or "legal obstacles," a new code has been published, to be 
used when legal demands require access to a page be blocked: error 451.
 
 
The number is a knowing reference Fahrenheit 451,
 the novel by Ray Bradbury that depicted a dystopian future where books 
are banned for spreading dissenting ideas, and in burned as a way censor
 the spread of information. The code itself was approved for use by the 
Internet Engineering Steering Group (IESG), which helps maintain 
internet standards.
 
The idea for code 451 originally came about around 3 years ago, when a
 UK court ruling required some websites to block The Pirate Bay. Most 
sites in turn used the 403 "forbidden" code, making it unclear to users 
about what the issue was. The goal of 451 is to eliminate some of the 
confusion around why sites may be blocked. 
 
The use of the code is completely voluntary, however, and requires 
developers to begin adopting it. But if widely implemented, it should be
 able to communicate to users that some information has been taken down 
because of a legal demand, or is being censored by a national 
government.