From: Simon Lyall (simon@darkmere.gen.nz)
Date: Mon Nov 10 1997 - 20:39:15 CST
catching up :(
-- Simon Lyall. | Looking for Work | Mail: simon@darkmere.gen.nz "To stay awake all night adds a day to your life" - Stilgar | MT.Changes:
- Played around with the language at the end. - Added bit about cancels etc..
x.x. Expires
The Expires header content specifies a date and time after that which the article is deemed to be no longer useful and SHOULD be removed ("expired"). The content syntax is the same as that of the Date header, content which is defined in the Message Format Standard [MESSFOR] .
Expires-content = date-time
The Expires header has two main applications: removing articles whose utility ends on a specific date (eg event announcements which can be removed once the day of the event is past) and preserving articles expected to be of prolonged usefulness (eg information aimed at new readers of a newsgroup).
Since individual hosts have local policies for expiration of news (depending on available disk space, for instance), posters SHOULD not provide Expires headers for articles unless there is a natural expiration date associated with the topic. Each serving agent SHOULD obey any reasonable value of this header but authors SHOULD NOT depend on this for very small or large values (relative to the natural expiration date).
An expiry value is overridden by a supersede or cancel.