diff --git a/clang/test/CXX/drs/dr18xx.cpp b/clang/test/CXX/drs/dr18xx.cpp
--- a/clang/test/CXX/drs/dr18xx.cpp
+++ b/clang/test/CXX/drs/dr18xx.cpp
@@ -168,3 +168,60 @@
   b = static_cast<B&&>(b); // expected-error {{copy assignment operator is implicitly deleted}}
 #endif
 }
+
+namespace dr1894 { // dr1894: 3.8
+                   // NB: reusing dr407 test
+  struct S;
+  typedef struct S S;
+  void f() {
+    struct S *p;
+    {
+      typedef struct S S; // #dr1894-typedef-S-S
+      struct S *p;
+      // expected-error@-1 {{typedef 'S' cannot be referenced with a struct specifier}}
+      // expected-note@#dr1894-typedef-S-S {{here}}
+    }
+  }
+  struct S {};
+
+  namespace UsingDir {
+    namespace A {
+      struct S {}; // #dr1894-struct-S
+    }
+    namespace B {
+      typedef int S; // #dr1894-typedef-int-S
+    }
+    namespace C {
+      using namespace A;
+      using namespace B;
+      struct S s;
+      // expected-error@-1 {{ambiguous}}
+      // expected-note@#dr1894-struct-S {{candidate}}
+      // expected-note@#dr1894-typedef-int-S {{candidate}}
+    }
+    namespace D {
+      using A::S;
+      typedef struct S S;
+      struct S s;
+    }
+    namespace E {
+      typedef A::S S;
+      using A::S;
+      struct S s;
+    }
+    namespace F {
+      typedef A::S S;
+    }
+
+    namespace G {
+      using namespace A;
+      using namespace F;
+      struct S s;
+    }
+    namespace H {
+      using namespace F;
+      using namespace A;
+      struct S s;
+    }
+  }
+}
diff --git a/clang/test/CXX/drs/dr21xx.cpp b/clang/test/CXX/drs/dr21xx.cpp
--- a/clang/test/CXX/drs/dr21xx.cpp
+++ b/clang/test/CXX/drs/dr21xx.cpp
@@ -1,7 +1,9 @@
 // RUN: %clang_cc1 -std=c++98 -triple x86_64-unknown-unknown %s -verify -fexceptions -Wno-deprecated-builtins -fcxx-exceptions -pedantic-errors
 // RUN: %clang_cc1 -std=c++11 -triple x86_64-unknown-unknown %s -verify -fexceptions -Wno-deprecated-builtins -fcxx-exceptions -pedantic-errors
 // RUN: %clang_cc1 -std=c++14 -triple x86_64-unknown-unknown %s -verify -fexceptions -Wno-deprecated-builtins -fcxx-exceptions -pedantic-errors
-// RUN: %clang_cc1 -std=c++1z -triple x86_64-unknown-unknown %s -verify -fexceptions -Wno-deprecated-builtins -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++17 -triple x86_64-unknown-unknown %s -verify -fexceptions -Wno-deprecated-builtins -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++20 -triple x86_64-unknown-unknown %s -verify -fexceptions -Wno-deprecated-builtins -fcxx-exceptions -pedantic-errors
+// RUN: %clang_cc1 -std=c++2b -triple x86_64-unknown-unknown %s -verify -fexceptions -Wno-deprecated-builtins -fcxx-exceptions -pedantic-errors
 
 #if __cplusplus < 201103L
 // expected-error@+1 {{variadic macro}}
@@ -188,3 +190,60 @@
   B &B::operator=(B&&) = default; // expected-error {{would delete}} expected-note@-10{{inaccessible move assignment}}
 #endif
 }
+
+namespace dr2199 { // dr2199: 3.8
+                   // NB: reusing dr407 test
+  struct S;
+  typedef struct S S;
+  void f() {
+    struct S *p;
+    {
+      typedef struct S S; // #dr2199-typedef-S-S
+      struct S *p;
+      // expected-error@-1 {{typedef 'S' cannot be referenced with a struct specifier}}
+      // expected-note@#dr2199-typedef-S-S {{here}}
+    }
+  }
+  struct S {};
+
+  namespace UsingDir {
+    namespace A {
+      struct S {}; // #dr2199-struct-S
+    }
+    namespace B {
+      typedef int S; // #dr2199-typedef-int-S
+    }
+    namespace C {
+      using namespace A;
+      using namespace B;
+      struct S s;
+      // expected-error@-1 {{ambiguous}}
+      // expected-note@#dr2199-struct-S {{candidate}}
+      // expected-note@#dr2199-typedef-int-S {{candidate}}
+    }
+    namespace D {
+      using A::S;
+      typedef struct S S;
+      struct S s;
+    }
+    namespace E {
+      typedef A::S S;
+      using A::S;
+      struct S s;
+    }
+    namespace F {
+      typedef A::S S;
+    }
+
+    namespace G {
+      using namespace A;
+      using namespace F;
+      struct S s;
+    }
+    namespace H {
+      using namespace F;
+      using namespace A;
+      struct S s;
+    }
+  }
+}
diff --git a/clang/test/CXX/drs/dr4xx.cpp b/clang/test/CXX/drs/dr4xx.cpp
--- a/clang/test/CXX/drs/dr4xx.cpp
+++ b/clang/test/CXX/drs/dr4xx.cpp
@@ -124,6 +124,7 @@
 }
 
 namespace dr407 { // dr407: 3.8
+                  // NB: reused by dr1894 and dr2199
   struct S;
   typedef struct S S;
   void f() {
diff --git a/clang/www/cxx_dr_status.html b/clang/www/cxx_dr_status.html
--- a/clang/www/cxx_dr_status.html
+++ b/clang/www/cxx_dr_status.html
@@ -11171,7 +11171,7 @@
     <td><a href="https://wg21.link/cwg1894">1894</a></td>
     <td>CD6</td>
     <td><I>typedef-name</I>s and <I>using-declaration</I>s</td>
-    <td class="none" align="center">Unknown</td>
+    <td class="full" align="center">Clang 3.8</td>
   </tr>
   <tr id="1895">
     <td><a href="https://wg21.link/cwg1895">1895</a></td>
@@ -13001,7 +13001,7 @@
     <td><a href="https://wg21.link/cwg2199">2199</a></td>
     <td>CD6</td>
     <td>Typedefs and tags</td>
-    <td class="none" align="center">Unknown</td>
+    <td class="full" align="center">Clang 3.8</td>
   </tr>
   <tr id="2200">
     <td><a href="https://wg21.link/cwg2200">2200</a></td>