RFC 9505: A Survey of Worldwide Censorship Techniques
This document describes technical mechanisms employed in network
censorship that regimes around the world use for blocking or impairing
Internet traffic. It aims to make designers, implementers, and users of
Internet protocols aware of the properties exploited and mechanisms used
for censoring end-user access to information. This document makes no
suggestions on individual protocol considerations, and is purely
informational, intended as a reference. This document is a product of
the Privacy Enhancement and Assessment Research Group (PEARG) in the
IRTF.