Duplicate content when appending a digit to URLs

[henrywright]

When each of the URLs below are visited, the exact same content is displayed each time. Would search engines see this a duplicate content?

example.com/support/
example.com/support/2/ 
example.com/support/3/ 
example.com/support/4/ 
example.com/support/5/

Note that when I visit a page such as example.com/support/kyathhaggfa where kyathhaggfa is garbage, I get a 404 page. This is the behaviour I would expect to see when a digit is appended to a page or post URL.

Interestingly, I don't see the issue happening on tag pages such as the following:

example.com/tags/soccer/
example.com/tags/soccer/2/
example.com/tags/soccer/3/

This issue was originally raised at BuddyPress Trac but further investigation has revealed it to be happening on WordPress too.

BP Trac ticket:
​http://buddypress.trac.wordpress.org/ticket/5224

[SergeyBiryukov]

Duplicate of #11694, #21278, and #21464.