Clearly, there are certain features in Codeforces that seem to have access limits (opened for 2100+) that are not officially disclosed.
However, here is the list of features that only Div.1 people can use from my observation.
Streams — div1 people can advertise their streaming.
Uphack — div1 people can hack solution after system test.
Problem tag — div1 people can edit problem tags and possibly determine problem rating.
Catalog — div1 people can edit catalog.
Vote — div1 people vote weighted more than other.
Feel free to share if there is anything not mentioned here; there are probably a lot more.
