On a tabbed browser, a sequence of HN tabs looks like this:
(Y) Hacker News | Aa... (Y) Hacker News | Bb... (Y) Hacker News | Zz...
Where (Y) is the Y-combinator icon. So, I can see which tabs are HN, but I can't see what they are about (save for the 1st 1 or 2 letters of the title of the discussion, and a little browser-provided ellipsis).
If the "Hacker News |" was removed from the beginning of the title, I would still see that the tabs were HN, because of the YC icon. And I would also be able to see the first 15 or so characters of the title of the discussion, which would help the navigation.