%% You should probably cite rfc7232 instead of this I-D. @techreport{ietf-httpbis-p4-conditional-26, number = {draft-ietf-httpbis-p4-conditional-26}, type = {Internet-Draft}, institution = {Internet Engineering Task Force}, publisher = {Internet Engineering Task Force}, note = {Work in Progress}, url = {https://datatracker.ietf.org/doc/draft-ietf-httpbis-p4-conditional/26/}, author = {Roy T. Fielding and Julian Reschke}, title = {{Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests}}, pagetotal = 28, year = 2014, month = feb, day = 6, abstract = {The Hypertext Transfer Protocol (HTTP) is a stateless 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.}, }