diff --git a/README.md b/README.md
index 47772a4..5099139 100644
--- a/README.md
+++ b/README.md
@@ -61,6 +61,8 @@ Scope:
 
 - If you are halfway through typing a command but change your mind, hit **alt-#** to add a `#` at the beginning and enter it as a comment (or use **ctrl-a**, **#**, **enter**). You can then return to it later via command history.
 
+- If you want to type a command but you remember only the beginning, hit **tab** to complete your command or double hit **tab** to display all possibilities.
+
 - Use `xargs` (or `parallel`). It's very powerful. Note you can control how many items execute per line (`-L`) as well as parallelism (`-P`). If you're not sure if it'll do the right thing, use `xargs echo` first. Also, `-I{}` is handy. Examples:
 ```bash
       find . -name '*.py' | xargs grep some_function