Index: clang-tidy/google/FunctionNamingCheck.cpp
===================================================================
--- clang-tidy/google/FunctionNamingCheck.cpp
+++ clang-tidy/google/FunctionNamingCheck.cpp
@@ -110,10 +110,12 @@
 void FunctionNamingCheck::check(const MatchFinder::MatchResult &Result) {
   const auto *MatchedDecl = Result.Nodes.getNodeAs<FunctionDecl>("function");
 
+  bool IsGlobal = MatchedDecl->getStorageClass() != SC_Static;
   diag(MatchedDecl->getLocation(),
-       "function name %0 not using function naming conventions described by "
-       "Google Objective-C style guide")
-      << MatchedDecl << generateFixItHint(MatchedDecl);
+       "%select{static function|function in global namespace}1 named %0 must "
+       "%select{be in|have an appropriate prefix followed by}1 Pascal case as "
+       "required by Google Objective-C style guide")
+      << MatchedDecl << IsGlobal << generateFixItHint(MatchedDecl);
 }
 
 } // namespace objc
Index: test/clang-tidy/google-objc-function-naming.m
===================================================================
--- test/clang-tidy/google-objc-function-naming.m
+++ test/clang-tidy/google-objc-function-naming.m
@@ -3,28 +3,35 @@
 typedef _Bool bool;
 
 static bool ispositive(int a) { return a > 0; }
-// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: function name 'ispositive' not using function naming conventions described by Google Objective-C style guide
+// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: static function named 'ispositive'
+// must be in Pascal case as required by Google Objective-C style guide
 // CHECK-FIXES: static bool Ispositive(int a) { return a > 0; }
 
 static bool is_positive(int a) { return a > 0; }
-// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: function name 'is_positive' not using function naming conventions described by Google Objective-C style guide
+// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: static function named 'is_positive'
+// must be in Pascal case as required by Google Objective-C style guide
 // CHECK-FIXES: static bool IsPositive(int a) { return a > 0; }
 
 static bool isPositive(int a) { return a > 0; }
-// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: function name 'isPositive' not using function naming conventions described by Google Objective-C style guide
+// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: static function named 'isPositive'
+// must be in Pascal case as required by Google Objective-C style guide
 // CHECK-FIXES: static bool IsPositive(int a) { return a > 0; }
 
 static bool Is_Positive(int a) { return a > 0; }
-// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: function name 'Is_Positive' not using function naming conventions described by Google Objective-C style guide
+// CHECK-MESSAGES: :[[@LINE-1]]:13: warning: static function named 'Is_Positive'
+// must be in Pascal case as required by Google Objective-C style guide
 // CHECK-FIXES: static bool IsPositive(int a) { return a > 0; }
 
 static bool IsPositive(int a) { return a > 0; }
 
 bool ispalindrome(const char *str);
-// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function name 'ispalindrome' not using function naming conventions described by Google Objective-C style guide
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function in global namespace named
+// 'ispalindrome' must have an appropriate prefix followed by Pascal case as
+// required by Google Objective-C style guide
 
 static const char *md5(const char *str) { return 0; }
-// CHECK-MESSAGES: :[[@LINE-1]]:20: warning: function name 'md5' not using function naming conventions described by Google Objective-C style guide
+// CHECK-MESSAGES: :[[@LINE-1]]:20: warning: static function named 'md5' must be
+// in Pascal case as required by Google Objective-C style guide
 // CHECK-FIXES: static const char *Md5(const char *str) { return 0; }
 
 static const char *MD5(const char *str) { return 0; }
@@ -38,12 +45,16 @@
 static const char *StringFromNSString(id str) { return ""; }
 
 void ABLog_String(const char *str);
-// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function name 'ABLog_String' not using function naming conventions described by Google Objective-C style guide
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function in global namespace named
+// 'ABLog_String' must have an appropriate prefix followed by Pascal case as
+// required by Google Objective-C style guide
 
 void ABLogString(const char *str);
 
 bool IsPrime(int a);
-// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function name 'IsPrime' not using function naming conventions described by Google Objective-C style guide
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function in global namespace named
+// 'IsPrime' must have an appropriate prefix followed by Pascal case as required
+// by Google Objective-C style guide
 
 const char *ABURL(void) { return "https://clang.llvm.org/"; }
 
Index: test/clang-tidy/google-objc-function-naming.mm
===================================================================
--- test/clang-tidy/google-objc-function-naming.mm
+++ test/clang-tidy/google-objc-function-naming.mm
@@ -1,16 +1,19 @@
 // RUN: %check_clang_tidy %s google-objc-function-naming %t
 
 void printSomething() {}
-// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function name 'printSomething' not
-// using function naming conventions described by Google Objective-C style guide
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function in global namespace named
+// 'printSomething' must have an appropriate prefix followed by Pascal case as
+// required by Google Objective-C style guide
 
 void PrintSomething() {}
-// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function name 'PrintSomething' not
-// using function naming conventions described by Google Objective-C style guide
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function in global namespace named
+// 'PrintSomething' must have an appropriate prefix followed by Pascal case as
+// required by Google Objective-C style guide
 
 void ABCBad_Name() {}
-// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function name 'ABCBad_Name' not
-// using function naming conventions described by Google Objective-C style guide
+// CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function in global namespace named
+// 'ABCBad_Name' must have an appropriate prefix followed by Pascal case as
+// required by Google Objective-C style guide
 
 namespace {