diff --git a/HACKING b/HACKING
index 190722d5..b2ee6c37 100644
--- a/HACKING
+++ b/HACKING
@@ -110,7 +110,16 @@ is hard to read.
   The exceptions to this rule are for objects with __iterator__ set,
   and for XML objects (see README.E4X).
 
-* Use [] and {} rather than new Array/new Object.
+* Avoid using 'new' with constructors where possible, and use [] and
+  {} rather than new Array/new Object.
+  Right:
+    RegExp("^" + foo + "$")
+    Function(code)
+    new Date
+  Wrong:
+    new RegExp("^" + foo + "$")
+    new Function(code)
+    Date() // Right if you want a string-representation of the date
 
 * Don't use abbreviations for public methods
   Right: