When I check in online my boarding pass (Delta) usually says "INTL - Verify PASSPORT" at the top if the passport needs checking, or DOCS-OK if not. They will frequently give me a replacement boarding pass with DOCS-OK once it is checked, but I also have one with a "Checked" stamp across it instead.
However, in my experience I've never needed to go back to the main check-in (outside the TSA area) -Checking in fact on one occasion when I needed to go there anyway they looked atwith my passport but did not okay it and I still had to have it checked at the gate. Checking in with itboarding card when I get to the gate counter has always worked, and I have never been paged outsidebut yes, they will page you to visit the gate areacounter agent prior to starting boarding if you don't do it yourself. On the other hand, if my boarding pass doesn't have either statement (but I usually get toother airlines) I've never had a problem with just approaching the gate with plenty of time anyway)agent and asking "do you need to check my passport?" - but do be sensitive to how busy they are.