diff --git a/README.md b/README.md
index 5c798e1..a09d63e 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,14 @@ echo hello
 [/shroot]
 ````
 
+To filter outputlines, prepend them with `(out)`.  
+Don't put a space between the keyword and the output
+
+```
+lsusb -d 0781:55a3 -v | grep bcdUSB
+(out)bcdUSB               3.20
+```
+
 ## Variables / Fill your own
 
 Values that should be replaced by the reader are generally represented this way: