http://www.rfc-editor.org/rfc/rfc7669.txt
RFC 7669: Assigning Digital Object Identifiers to RFCs, J. Levine2015-10-01T23:00:00-00:00This document describes the way that Digital Object Identifiers (DOIs) are assigned to past and future RFCs. The DOI is a widely used system that assigns unique identifiers to digital documents that can be queried and managed in a consistent fashion.