The Amateur Radio Operator Certificate:

According to ISED regulations, your Amateur Radio Operator Certificate (or a physical copy of it) must be retained at the station. This ensures that proof of authorization is accessible where the transmitting equipment is located, in case an inspector visits the site. While keeping it in a safe place or on your person might sound like a good personal practice, these do not satisfy the specific legal requirement. The certificate validates your operating privileges at the station, making the station itself the legally required location for the document.