404 Not Found

   The 404 (Not Found) status code indicates that the origin server did
   not find a current representation for the target resource or is not
   willing to disclose that one exists.  A 404 status code does not
   indicate whether this lack of representation is temporary or
   permanent; the 410 (Gone) status code is preferred over 404 if the
   origin server knows, presumably through some configurable means, that
   the condition is likely to be permanent.

   A 404 response is cacheable by default; i.e., unless otherwise
   indicated by the method definition or explicit cache controls (see
   Section 4.2.2 of [RFC7234]).