diff --git a/CppCoreGuidelines.md b/CppCoreGuidelines.md
index 4dab763..743abdd 100644
--- a/CppCoreGuidelines.md
+++ b/CppCoreGuidelines.md
@@ -4036,7 +4036,7 @@ Many language and library facilities rely on default constructors to initialize
 The default constructor is only auto-generated if there is no user-declared constructor, hence it's impossible to initialize the vector `vd1` in the example above.
 
 There is no "natural" default date (the big bang is too far back in time to be useful for most people), so this example is non-trivial.
-`{0, 0, 0}` is not a valid date in most calendar systems, so choosing that would be introducing something like floating-point's NaN.
+`{0, 0, 0}` is not a valid date in most calendar systems, so choosing that would be introducing something like floating-point's `NaN`.
 However, most realistic `Date` classes have a "first date" (e.g. January 1, 1970 is popular), so making that the default is usually trivial.
 
 ##### Example