diff --git a/types/custom-functions-runtime/index.d.ts b/types/custom-functions-runtime/index.d.ts
index e233a869fd..b20d38828e 100644
--- a/types/custom-functions-runtime/index.d.ts
+++ b/types/custom-functions-runtime/index.d.ts
@@ -9,6 +9,13 @@ office-js
 Copyright (c) Microsoft Corporation
 */
 
+////////////////////////////////////////////////////////////////
+//////////////////// Begin custom-functions-runtime ////////////
+////////////////////////////////////////////////////////////////
+
+/*
+* Enables you to map your own name that uses lowercase letters to a function.
+*/
 declare let CustomFunctionMappings: { [key: string]: Function };
 
 declare namespace CustomFunctions {
@@ -28,3 +35,7 @@ declare namespace CustomFunctions {
         onCanceled: () => void;
     }
 }
+
+////////////////////////////////////////////////////////////////
+//////////////////// End custom-functions-runtime ////////////
+////////////////////////////////////////////////////////////////
diff --git a/types/custom-functions-runtime/tsconfig.json b/types/custom-functions-runtime/tsconfig.json
index 3c8cbbaf27..c42a495281 100644
--- a/types/custom-functions-runtime/tsconfig.json
+++ b/types/custom-functions-runtime/tsconfig.json
@@ -2,7 +2,7 @@
     "compilerOptions": {
         "module": "commonjs",
         "lib": [
-            "es6", 
+            "es6",
             "dom"
         ],
         "noImplicitAny": true,