diff --git a/src/librustc_error_codes/error_codes.rs b/src/librustc_error_codes/error_codes.rs
index 709ccce517a36..5b117bc740f57 100644
--- a/src/librustc_error_codes/error_codes.rs
+++ b/src/librustc_error_codes/error_codes.rs
@@ -28,6 +28,7 @@ E0029: include_str!("./error_codes/E0029.md"),
 E0030: include_str!("./error_codes/E0030.md"),
 E0033: include_str!("./error_codes/E0033.md"),
 E0034: include_str!("./error_codes/E0034.md"),
+E0036: include_str!("./error_codes/E0036.md"),
 E0038: include_str!("./error_codes/E0038.md"),
 E0040: include_str!("./error_codes/E0040.md"),
 E0044: include_str!("./error_codes/E0044.md"),
@@ -414,7 +415,6 @@ E0745: include_str!("./error_codes/E0745.md"),
 //  E0006, // merged with E0005
 //  E0008, // cannot bind by-move into a pattern guard
 //  E0035, merged into E0087/E0089
-//  E0036, merged into E0087/E0089
 //  E0068,
 //  E0085,
 //  E0086,
diff --git a/src/librustc_error_codes/error_codes/E0036.md b/src/librustc_error_codes/error_codes/E0036.md
new file mode 100644
index 0000000000000..a74a510c7a7c4
--- /dev/null
+++ b/src/librustc_error_codes/error_codes/E0036.md
@@ -0,0 +1,40 @@
+#### Note: this error code is no longer emitted by the compiler.
+
+This error occurrs when you pass too many or not enough type parameters to
+a method. Erroneous code example:
+
+```compile_fail,E0107
+struct Test;
+impl Test {
+    fn method<T>(&self, v: &[T]) -> usize {
+        v.len()
+    }
+}
+fn main() {
+    let x = Test;
+    let v = &[0];
+    x.method::<i32, i32>(v); // error: only one type parameter is expected!
+}
+```
+
+To fix it, just specify a correct number of type parameters:
+
+```
+struct Test;
+impl Test {
+    fn method<T>(&self, v: &[T]) -> usize {
+        v.len()
+    }
+}
+fn main() {
+    let x = Test;
+    let v = &[0];
+    x.method::<i32>(v); // OK, we're good!
+}
+```
+
+Please note on the last example that we could have called `method` like this:
+
+```text
+x.method(v);
+```
diff --git a/src/librustc_error_codes/error_codes/E0066.md b/src/librustc_error_codes/error_codes/E0066.md
new file mode 100644
index 0000000000000..58df1debeaf3d
--- /dev/null
+++ b/src/librustc_error_codes/error_codes/E0066.md
@@ -0,0 +1,9 @@
+#### Note: this error code is no longer emitted by the compiler.
+
+Box placement expressions (like C++'s "placement new") do not yet support any
+place expression except the exchange heap (i.e. `std::boxed::HEAP`).
+Furthermore, the syntax is changing to use `in` instead of `box`. See [RFC 470]
+and [RFC 809] for more details.
+
+[RFC 470]: https://github.com/rust-lang/rfcs/pull/470
+[RFC 809]: https://github.com/rust-lang/rfcs/pull/809