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+#### Note: this error code is no longer emitted by the compiler.
+
+`where` clauses must use generic type parameters: it does not make sense to use
+them otherwise. An example causing this error:
+
+```
+trait Foo {
+    fn bar(&self);
+}
+
+#[derive(Copy,Clone)]
+struct Wrapper<T> {
+    Wrapped: T
+}
+
+impl Foo for Wrapper<u32> where Wrapper<u32>: Clone {
+    fn bar(&self) { }
+}
+```
+
+This use of a `where` clause is strange - a more common usage would look
+something like the following:
+
+```
+trait Foo {
+    fn bar(&self);
+}
+
+#[derive(Copy,Clone)]
+struct Wrapper<T> {
+    Wrapped: T
+}
+impl <T> Foo for Wrapper<T> where Wrapper<T>: Clone {
+    fn bar(&self) { }
+}
+```
+
+Here, we're saying that the implementation exists on Wrapper only when the
+wrapped type `T` implements `Clone`. The `where` clause is important because
+some types will not implement `Clone`, and thus will not get this method.
+
+In our erroneous example, however, we're referencing a single concrete type.
+Since we know for certain that `Wrapper<u32>` implements `Clone`, there's no
+reason to also specify it in a `where` clause.