It is (still) a language notice (English, Spanish, Chinese, etc.) irrespective of what other notice you are getting. In my case the notice accompanied a letter I received confirming acceptance of my amended return. In your case it (the language form) is accompanying some other notice (the substance of why they are writing you), as you indicated you did not file an amended return. So, in short, when the person above answered you by indicating the answer to your inquiry was already addressed above, they were indeed correct - the IRS does not have more than one type of form to a corresponding form number, as that would be ridiculously confusing.
