diff --git a/README.asciidoc b/README.asciidoc
index 372c3944..c6540630 100644
--- a/README.asciidoc
+++ b/README.asciidoc
@@ -116,6 +116,8 @@ Just running *kak* launch a new kak session with a client on local terminal.
        will quit when receiving SIGTERM.
  * +-p <session>+: read stdin, and then send its content to the given session
        acting as a remote control.
+ * +-f <keys>+: Work as a filter, read every file given on the command line
+       and stdin if piped in, and apply given keys on each.
 
 At startup, if +-n+ is not specified, Kakoune will try to source the file
 ../share/kak/kakrc relative to the kak binary. This kak file will then try