ShadowsocksR

ShadowsocksR branched from Shadowsocks to add an extensible protocol and obfuscation layer, expressed in share links as protocol, obfs and their parameters. It gained wide usage around 2015 but development stopped years ago, and most modern clients support it only for compatibility. SSR links carry a base64-wrapped body containing host, port, method, password and the plugin settings. New deployments generally prefer Shadowsocks with plugins or newer protocols, but archives of public SSR configs still circulate.