diff --git a/d00/ex02/Account.cpp b/d00/ex02/Account.cpp
index 169cc77..f2cd114 100644
--- a/d00/ex02/Account.cpp
+++ b/d00/ex02/Account.cpp
@@ -3,7 +3,8 @@
 #include <iomanip>
 #include <ctime>
 
-// to compare output : 
+// to compare output : diff <(cut -d \  -f 2 file1) <(cut -d \  -f 2 file2)
+// it's process substitution : https://www.gnu.org/software/bash/manual/html_node/Process-Substitution.html
 
 void	Account::displayAccountsInfos( void ) {