diff --git a/includes/_internal.h b/includes/_internal.h
index 5114c1a..c19c1da 100644
--- a/includes/_internal.h
+++ b/includes/_internal.h
@@ -52,6 +52,13 @@ char	*itoa_base(uint64_t nbr, char *base);
  */
 int		flag_c(va_list args, int fd);
 
+/**
+ * @brief Function to handle the flag i in printf's function
+ *
+ * @param args list of arguments
+ * @param fd file descriptor
+ * @return The number of character write in the fd
+ */
 int		flag_i(va_list args, int fd);
 
 int		flag_p(va_list args, int fd);