diff --git a/readme b/readme
index 588f318..3753109 100644
--- a/readme
+++ b/readme
@@ -11,6 +11,8 @@ ghc -dynamic --make Main.hs -o factory
 
 # Symbol overview
  - E: The entrypoint. This is where the first element is spawned.
+ - X: The exitpoint. If an element reaches a tile like this, the program will
+      exit with the value of the element as the exit value.
  - >: Track going east.
  - v: Track going south.
  - <: Track going west.