226 IM Used

Note: Browsers don't support delta encoding with HTTP. This status code is sent back by custom servers used by specific clients.

In the context of delta encodings, the HTTP 226 IM Used status code is set by the server to indicate that it is returning a delta to the GET request that it received.

With delta encoding a server responds to GET requests with differences (called deltas) relative to a given base document (rather than the current document). The client uses the A-IM: HTTP header to indicate which differencing algorithm to use and the If-None-Match: header to hint the server about the last version it got. The server generates a delta, sending it back in an HTTP response with the 226 status code and containing the IM: (with the name of the algorithm used) and Delta-Base: (with the ETag matching the base document associated to the delta) HTTP headers.

IM stands for instance manipulations the term used to describe an algorithm generating a delta.


226 IM Used


Unknown specification
# section-10.4.1