An appropriate HTTP status message should be presented to the user/agent when an error condition occurs.
Benefits of conformance
- Consistent, quality experience for users of the site.
- Increased site credibility and levels of user trust.
- Increased likelihood that a user will find what they were looking for online.
Risks of non-conformance
- Possible increase in offline channel requests for inexplicably removed information.
- Reduced site credibility and levels of user trust.
When not due to user error, these conditions largely represent a break-down in the normal operation of a production server.
In the case of user error, the nature of the problem should be relayed to the user in as much detail as necessary for the user to understand what they can do to fix the problem.
Sometimes a user input error condition can be predicted and an alternate course of action can be suggested. For example: if the user enters a common typographical error or misspelling, a link to the correct URL can be provided to the user (see Aliasing a resource).
In the case of internal server errors, it is often useful to email or otherwise alert the site’s administration team when they occur and inform the user that they have been notified.