Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests

Document Name:	RFC 7232
Document URI:	`urn:ietf:rfc:7232`
Online Version:	`https://datatracker.ietf.org/doc/html/rfc7232`
Organization:	Internet Engineering Task Force (IETF)
Series:	Request for Comments (RFC)
Abstract:	The Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed, collaborative, hypertext information systems. This document defines HTTP/1.1 conditional requests, including metadata header fields for indicating state changes, request header fields for making preconditions on such state, and rules for constructing the responses to a conditional request when one or more preconditions evaluate to false.

Specified Web Concepts:


   ETag


   If-Match


   If-Modified-Since


   If-None-Match


   If-Unmodified-Since


   Last-Modified