Where can I learn what this means? "has static page, has static URL"

What Im trying to accomplish is that I have an item with a couple of dozen people waiting for it to come into stock, but I need to change the reference # due to the item changing slightly, but enough so that I need to keep track.
When I do this, the link sent with the email notification won't work. Im trying to figure a workaround.

Hi, I'm not sure you can get those notices to customers if you change the product ID, or attempt to make use of the static page or URL.
However, you can read about that here on this page - https://www.ecommercetemplates.com/help/admin-products.asp

Thanks,
David