CommonApp not properly filled in.......is it too bad?

Greetings to all,
Well, I didn’t mess up the whole application, but in the fields for secondary schools I listed only the high-school I am currently attending. I have also attended a language school (more like a summer school or something) for which I have attached 2 certificates and a sealed recommendation. Is it that bad when enclosing sth that is not noted on the application?
thx.

<p>shouldnt be a big deal. i understand that you can send a letter to make that correction at some schools.</p>