diff --git a/C++GUIDE.md b/C++GUIDE.md
index cfcd900..bad8f81 100644
--- a/C++GUIDE.md
+++ b/C++GUIDE.md
@@ -48,12 +48,12 @@ Copyright © 2022 Concordia CERC group
 Project Coder Guillermo Gutierrez Morote <Guillermo.GutierrezMorote@concordia.ca>
 */
 
-#ifndef SAMPLE_PERSON_H_
-#define SAMPLE_PERSON_H_
+#ifndef SAMPLE_PERSON_HPP_
+#define SAMPLE_PERSON_HPP_
 
 ...
 
-#endif  //SAMPLE_PERSON_H_
+#endif  //SAMPLE_PERSON_HPP_
 
 ```
 
@@ -70,15 +70,15 @@ Copyright © 2022 Concordia CERC group
 Project Coder Guillermo Gutierrez Morote <Guillermo.GutierrezMorote@concordia.ca>
 */
 
-#ifndef SAMPLE_PERSON_H_
-#define SAMPLE_PERSON_H_
+#ifndef SAMPLE_PERSON_HPP_
+#define SAMPLE_PERSON_HPP_
 
 namespace sample {
 
 
 }
 
-#endif  //SAMPLE_PERSON_H_
+#endif  //SAMPLE_PERSON_HPP_
 
 ```
 
@@ -99,8 +99,8 @@ Copyright © 2022 Concordia CERC group
 Project Coder Guillermo Gutierrez Morote <Guillermo.GutierrezMorote@concordia.ca>
 */
 
-#ifndef SAMPLE_PERSON_H_
-#define SAMPLE_PERSON_H_
+#ifndef SAMPLE_PERSON_HPP_
+#define SAMPLE_PERSON_HPP_
 
 #include <string>
 
@@ -109,7 +109,7 @@ namespace sample {
 
 }
 
-#endif  //SAMPLE_PERSON_H_
+#endif  //SAMPLE_PERSON_HPP_
 
 ```
 
@@ -133,6 +133,10 @@ namespace sample {
 
 Ensure that your imports are used and remove any unused.
 
+### Indentation
+
+We indent with 2 spaces as it's considered more consistent when using different editors and operationg systems while provide enoug readability for the hierarchies. 
+
 ### Multiplatform
 
 CERC team is aiming to create platform independent open software, therefore the use of platform specific libraries is discouraged, if such thing can't be avoided, try to provide platform alternatives by using compiler directives.
@@ -184,8 +188,8 @@ Project Coder Guillermo Gutierrez Morote <Guillermo.GutierrezMorote@concordia.ca
 
 /// \file person.hpp
 
-#ifndef SAMPLE_PERSON_H_
-#define SAMPLE_PERSON_H_
+#ifndef SAMPLE_PERSON_HPP_
+#define SAMPLE_PERSON_HPP_
 
 #include <string>
 
@@ -203,7 +207,7 @@ namespace sample {
   }
 }
 
-#endif  //SAMPLE_PERSON_H_
+#endif  //SAMPLE_PERSON_HPP_
 
 ```