diff --git a/CppCoreGuidelines.md b/CppCoreGuidelines.md
index 209060b..06c16fc 100644
--- a/CppCoreGuidelines.md
+++ b/CppCoreGuidelines.md
@@ -5965,6 +5965,7 @@ Here, we ignore such cases.
* [R.15: Always overload matched allocation/deallocation pairs](#Rr-pair)
* Smart pointer rule summary:
+
* [R.20: Use `unique_ptr` or `shared_ptr` to represent ownership](#Rr-owner)
* [R.21: Prefer `unique_ptr` over `shared_ptr` unless you need to share ownership](#Rr-unique)
* [R.22: Use `make_shared()` to make `shared_ptr`s](#Rr-make_shared)
@@ -6841,7 +6842,7 @@ Arithmetic rules:
* [ES.101: use unsigned types for bit manipulation](#Res-unsigned)
* [ES.102: Used signed types for arithmetic](#Res-signed)
* [ES.103: Don't overflow](#Res-overflow)
-* [ES.104: Don't underflow](#Res-overflow)
+* [ES.104: Don't underflow](#Res-underflow)
* [ES.105: Don't divide by zero](#Res-zero)
### ES.1: Prefer the standard library to other libraries and to "handcrafted code"
@@ -8460,7 +8461,7 @@ Incrementing a value beyond a maximum value can lead to memory corruption and un
???
-### ES.104: Don't underflow
+### ES.104: Don't underflow
##### Reason
@@ -10589,7 +10590,8 @@ In many cases you can provide a stable interface by not parameterizing a base; s
##### Enforcement
* Flag virtual functions that depend on a template argument. ??? False positives
- ### T.81: Do not mix hierarchies and arrays
+
+### T.81: Do not mix hierarchies and arrays
##### Reason
@@ -11101,6 +11103,7 @@ Use a C++ compiler.
##### Enforcement
* Flag if using a build mode that compiles code as C.
+
* The C++ compiler will enforce that the code is valid C++ unless you use C extension options.
### CPL.3: If you must use C for interfaces, use C++ in the calling code using such interfaces
@@ -13349,7 +13352,7 @@ Alternatively, we will decide that no change is needed and delete the entry.
\[Meyers96\]: S. Meyers. More Effective C++ (Addison-Wesley, 1996).
*
\[Meyers97\]: S. Meyers. Effective C++ (2ndEdition) (Addison-Wesley, 1997).
-*
+*
\[Meyers14\]: S. Meyers. Effective Modern C++ (Addison-Wesley, 2014).
*
\[Murray93\]: R. Murray. C++ Strategies and Tactics (Addison-Wesley, 1993).