diff --git a/docs/cmdline-opts/_PROTOCOLS.md b/docs/cmdline-opts/_PROTOCOLS.md
index 0d4c2374ef..af7019ab0a 100644
--- a/docs/cmdline-opts/_PROTOCOLS.md
+++ b/docs/cmdline-opts/_PROTOCOLS.md
@@ -49,3 +49,5 @@ Fetching a telnet URL starts an interactive session where it sends what it
 reads on stdin and outputs what the server sends it.
 ## TFTP
 curl can do TFTP downloads and uploads.
+## WS(S)
+WebSocket done over HTTP/1. WSS implies that it works over HTTPS.