diff --git a/CppCoreGuidelines.md b/CppCoreGuidelines.md
index 7c8607c..ae8f7a0 100644
--- a/CppCoreGuidelines.md
+++ b/CppCoreGuidelines.md
@@ -18755,7 +18755,7 @@ Distinguishing these alternatives prevents misunderstandings and bugs.
 All we know is that it is supposed to be the nullptr or point to at least one character
 
     void f1(zstring s);     // s is a C-style string or the nullptr
-    void f1(czstring s);    // s is a C-style string that is not the nullptr
+    void f1(czstring s);    // s is a C-style string constant or the nullptr
     void f1(std::byte* s);  // s is a pointer to a byte (C++17)
 
 ##### Note