hi! I asked NNAs about the content of the waiver and here is their reply.
"Since you are applying to Ontario, you have the option to either send in your IELTS/CELBAN results, or waive/postpone the language requirement by writing NNAS a letter indicating that choice. This way, your Advisory report can be issued without IELTS/CELBAN results (knowing that Ontario will contact you after you sit for the Exam about their language proficiency requirement). If you choose to postpone the language, you must write a letter stating that you are an Ontario Applicant, and you wish to waive the Language requirement from your NNAS Application, your NNAS ID number and signature. Please send the letter by postal mail to NNAS, 3600 Market Street, Suite 400, Philadelphia PA 19104-2651, USA. Please feel free to contact us if you have any further questions. NNAS Customer Care"