%% You should probably cite rfc7232 instead of this I-D. @techreport{ietf-httpbis-p4-conditional-20, number = {draft-ietf-httpbis-p4-conditional-20}, 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/20/}, author = {Roy T. Fielding and Yves Lafon and Julian Reschke}, title = {{HTTP/1.1, part 4: Conditional Requests}}, pagetotal = 26, year = 2012, month = jul, day = 16, 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.}, }