For example, this article mentions symbols VZ.N, CVC.N, TWC.N, and CCOI.O.
Are these related to share classes and/or warrants? Each of these symbols also seem to exist and can be referenced without the suffix.
I don't see those particular suffixes in this table
I notice that on the stock pages (i.e. CVC.N) the stats vary between the suffixed (CVC.N) and non-suffixed (CVC) versions.