update of disclaimer

subjects/nauuo.en.md

@@ -1,5 +1,16 @@
 ## nauuo
 
+## **WARNING! VERY IMPORTANT!**
+
+For this exercise a function will be tested **with the exam own main**. However the student **still needs** to submit a structured program:
+
+This means that:
+
+- The package needs to be named `package main`.
+- The submitted code needs one declared function main(```func main()```) even if empty.
+- The function main declared needs to **also pass** the `Restrictions Checker`(illegal functions tester). It is advised for the student to just empty the function main after its own testings are done.
+- Every other rules are obviously the same than for a `program`.
+
 ### Instructions
 
 There was a vote. There are people who voted positively, negatively, and randomly. 
@@ -46,4 +57,4 @@ student@ubuntu:~/[[ROOT]]/test$ ./test
 +
 -
 student@ubuntu:~/[[ROOT]]/test$
-```
+```