Servers tolerating bad HTTP clients

W3C HTTP 1992

Note: Server tolerance of bad clients

Whilst it is seen appropriate for testing parsers to check full conformance to this specification, it is recommended that operational parsers be tolerant of deviations.

In particular, lines should be regarded as terminated by the Line Feed, and the preceeding Carriage Return character ignored.

Any HTTP Header Field Name which is not recognised should be ignored in operational parsers.

It is recommended that servers use URIs free of "variant" characters whose representation differs in some of the national variant character sets, punctuation characters, and spaces. This will make URIs easier to handle by humans when the need (such as debugging, or transmission through non hypertext systems) arises.