Address with a numeric suffix
If the page is a duplicate, it competes with you in search results. If it is page 2 of a series, that is fine. From outside we cannot tell; you can.
When we count it as met
When we measure again, none of the measured pages has an address ending in a numeric suffix.
How to check it yourself
Confirm it in the address bar: the address no longer ends in a number.
Measure it on your site
UXMachine measures it in a real browser, on desktop and mobile, together with the other checks.