diff --git a/in/public/code/c/index.rst b/in/public/code/c/index.rst
index f6f74d5..a0374ac 100644
--- a/in/public/code/c/index.rst
+++ b/in/public/code/c/index.rst
@@ -16,6 +16,13 @@ Comments
  // single line comment
  /* multi line comment */
 
+Constants
+---------
+
+.. code:: c
+
+ #define NUMERIC_CONSTANT 123
+
 Main
 ----