diff --git a/CppCoreGuidelines.md b/CppCoreGuidelines.md
index 770c235..2ef163b 100644
--- a/CppCoreGuidelines.md
+++ b/CppCoreGuidelines.md
@@ -16068,8 +16068,8 @@ Source file rule summary:
* [SF.3: Use `.h` files for all declarations used in multiple source files](#Rs-declaration-header)
* [SF.4: Include `.h` files before other declarations in a file](#Rs-include-order)
* [SF.5: A `.cpp` file must include the `.h` file(s) that defines its interface](#Rs-consistency)
-* [SF.6: Use `using`-directives for transition, for foundation libraries (such as `std`), or within a local scope](#Rs-using)
-* [SF.7: Don't put a `using`-directive in a header file](#Rs-using-directive)
+* [SF.6: Use `using namespace` directives for transition, for foundation libraries (such as `std`), or within a local scope](#Rs-using)
+* [SF.7: Don't write `using namespace` in a header file](#Rs-using-directive)
* [SF.8: Use `#include` guards for all `.h` files](#Rs-guards)
* [SF.9: Avoid cyclic dependencies among source files](#Rs-cycles)
@@ -16271,7 +16271,7 @@ The argument-type error for `bar` cannot be caught until link time because of th
???
-### SF.6: Use `using`-directives for transition, for foundation libraries (such as `std`), or within a local scope
+### SF.6: Use `using namespace` directives for transition, for foundation libraries (such as `std`), or within a local scope
##### Reason
@@ -16285,7 +16285,7 @@ The argument-type error for `bar` cannot be caught until link time because of th
???
-### SF.7: Don't put a `using`-directive in a header file
+### SF.7: Don't write `using namespace` in a header file
##### Reason
@@ -16293,11 +16293,22 @@ Doing so takes away an `#include`r's ability to effectively disambiguate and to
##### Example
- ???
+ // bad.h
+ #include
+ using namespace std; // bad
+
+ // user.cpp
+ #include "bad.h"
+
+ bool copy( /*... some parameters ...*/); // some function that happens to be named copy
+
+ int main() {
+ copy( /*...*/ ); // now overloads local ::copy and std::copy, could be ambiguous
+ }
##### Enforcement
-???
+Flag `using namespace` at global scope in a header file.
### SF.8: Use `#include` guards for all `.h` files