Have you ever noticed misspelled HTTP response headers?
$ http -h http://www.dmoz.org/Computers/Programming/Languages/Python/Books/ HTTP/1.1 200 OK Connection: close Content-Encoding: gzip Content-Language: en Content-Length: 9907 Content-Type: text/html;charset=UTF-8 Cteonnt-Length: 33416 Date: Tue, 12 Apr 2016 12:26:06 GMT Server: Apache
That ‘Cteonnt-Length’ sure looks weird!
According to this StackOverflow answer, the jumbled header contains the uncompressed size of the response and, sure enough, it does seem to be the case. But why?
It seems like this is a trick employed by hardware appliances (eg Citrix NetScaler) to ‘remove’ a header without affecting the check-sum value.