observers online?

this is an old question of mine, but i let it be, as i wasnt interested in watching pvp that much

but in case it ever gets back to being real active again (now its somewhat active), how can i see there are more observers?
they said with "O" back then, but i only saw team stuff and such, isnt that for the match you are watching?

still curious, even though i dont pvp myself, i might sometimes watch a battle or 2, just wanna know this

If you type something into the chat window it'll tell you if no one else hears it.
If you join an observer session and it's already started, that means you've joined a session begun by somebody else (thus you're probably not alone).

Afaik that's as much info as you can glean.