diff --git a/docs/TODO b/docs/TODO
index 1d43e7f63..b288e4dbb 100644
--- a/docs/TODO
+++ b/docs/TODO
@@ -134,6 +134,7 @@
  18.1 sync
  18.2 glob posts
  18.3 prevent file overwriting
+ 18.4 --proxycommand
  18.5 UTF-8 filenames in Content-Disposition
  18.7 at least N milliseconds between requests
  18.9 Choose the name of file in braces for complex URLs
@@ -869,6 +870,16 @@ that doesn't exist on the server, just like --ftp-create-dirs.
  existing). So that index.html becomes first index.html.1 and then
  index.html.2 etc.
 
+18.4 --proxycommand
+
+ Allow the user to make curl run a command and use its stdio to make requests
+ and not do any network connection by itself. Example:
+
+   curl --proxycommand 'ssh pi@raspberrypi.local -W 10.1.1.75 80' \
+        http://some/otherwise/unavailable/service.php
+
+ See https://github.com/curl/curl/issues/4941
+
 18.5 UTF-8 filenames in Content-Disposition
 
  RFC 6266 documents how UTF-8 names can be passed to a client in the