I found this, but again I am not too sure if it makes sense in your context.
https://valleynaturopath.ca/10-myths-naturopathic-medicine/You can find out more about natural health product regulation here. Currently, all natural health products (NHP’s) must have a Natural Product Number (NPN) or an exception number (EN) to be sold legally in Canada. In order to obtain an NPN or an EN, an application must be filed with the Natural Heath Product Directorate (NHPD). The application includes evidence of safety, efficacy, and quality. It should also mean the product has been tested for contaminants, yet this does not always occur. An EN means the NHPD acknowledges that it has received an application for a product, but that it has not had time to evaluate the product.
So, "EN" > Exception Number, but the link provided is from Canada.