The competition clause of my consultancy agreement contains that
The resignation means that the consultant is ineligible during 1 year after the retirement date to begin, take employment with, or directly or indirectly interested in any business wholly or partly competes with the business which the company operates at the consultant's resignation.
What is the official way to prove that I terminated a contract on a certain date? If 1 year after the terminated I will start business in the same industry I would no get into any trouble.
Is it enough if I have sent e-mail to the CEO?