diff --git a/site/versions/master/docs/skylark/concepts.md b/site/versions/master/docs/skylark/concepts.md
index dc749c4..ecf49b8 100644
--- a/site/versions/master/docs/skylark/concepts.md
+++ b/site/versions/master/docs/skylark/concepts.md
@@ -162,7 +162,7 @@
 
 * Sets have reference equality semantics and can be stored in other sets.
 
-* Lists and other mutable values may be stored in sets and in dictionary
+* Lists and other mutable types may be stored in sets and in dictionary
   keys once they are frozen.
 
 * Modifying a collection during iteration is an error. You can avoid the error
@@ -187,9 +187,6 @@
   deterministic. As an implementation matter, some kinds of dictionaries may
   continue to use sorted order while others may use insertion order.
 
-* Some collections currently use reference equality (sometimes inconsistently).
-  This will change to structural equality for all collections except sets.
-
 * The `+=` operator and similar operators are currently syntactic sugar;
   `x += y` is the same as `x = x + y`. This will change to follow Python
   semantics, so that for mutable collection datatypes, `x += y` will be a
@@ -203,6 +200,14 @@
   `dict(a.items() + b.items())`. Likewise, there is a `+` operator for sets that
   will be going away; users should use `|` instead.
 
+* The order comparison operators (<, <=, >=, >) are currently defined across
+  different types of values, e.g., you can write `5 < 'foo'`. This will be an
+  error, just like in Python 3. Note that this means you will be unable to
+  sort lists that contain mixed types of values.
+
+* The set datatype will be renamed in order to avoid confusion with Python's
+  set datatype, which behaves very differently.
+
 The following Python features are not supported:
 
 * `class` (see [`struct`](lib/globals.html#struct) function)