Re: HTTP HEAD requests for Last-Modified info

Dave Cole <>
|Returning of Last-Modified is server dependent.

draft-ietf-http-v11-spec-05.txt [1], what will be HTTP 1.1 strongly encourages
sending Last-Modified:

|HTTP/1.1 servers SHOULD send Last-Modified whenever feasible.

Caching can't function to its potential if servers don't advertise L-M whenever
possible.  Caching is essential to HTTP scalability in the near-term.  Server
authors: N.B. above.

And both above and RFC1954 [HTTP 1.0][2] discuss possible meanings for
Last-Modified based on the type of resource to which a method applies:

|The exact meaning of this header field depends on the implementation of
|the origin server and the nature of the original resource. For files, it
|may be just the file system last-modified time. For entities with
|dynamically included parts, it may be the most recent of the set of
|last-modify times for its component parts. For database gateways, it may
|be the last-update time stamp of the record. For virtual objects, it may
|be the last time the internal state changed.



Received on Thursday, 20 June 1996 13:30:59 UTC