diff --git a/src/jrex/Expressions.java b/src/jrex/Expressions.java
index 043d99c..1d83a5e 100644
--- a/src/jrex/Expressions.java
+++ b/src/jrex/Expressions.java
@@ -3,6 +3,7 @@
 import java.util.List;
 
 /**
+ * Used for holding state to be (de)serialised into JSON when saving/loading the expressions.
  *
  * @author mark
  */