diff --git a/CONTRIBUTING.rst b/CONTRIBUTING.rst
index 4224ba500..8e4d1241b 100644
--- a/CONTRIBUTING.rst
+++ b/CONTRIBUTING.rst
@@ -405,4 +405,11 @@ Example:
 
 i.MX 8MP uses a different ``mmc`` command from master and from the rest of the
 i.MX 8M family. The content will be split again and i.MX 8MP needs to use its
-own specific version (different file).
+yash own specific version (different file).
+
+How to use substitution after dot "." in descriptions?
+------------------------------------------------------
+
+To  use substitution variable in descriptions after a dot "." it need to 
+specified as the following "./ |substitution_variable|" in descriptions. A sample 
+example is below.