May be involventarily denied boarding tomorrow
 

I've just checked into my flight for OA334 tomorrow. (ATH-CHQ) [Ageian purchased Olympic Air metal] and I've been told that I can't get a boarding pass because my status is "Standby". The ticket purchased is via Agenian airlines on a Flex ticket and ticket class V.

What are my rights? It's a fully purchased ticket and it sounds like I'm being screwed out of my flight.

What are the things that I'll need for EU261 comp?

When did you buy your ticket? Did you check-in on the OA or the A3 site?

Bought: 2 April on Agenan's site.
Checkin was prompted by OA.

I can't find a way to checkin via A3.

Just wait and see whether you'll get on the flight or not before freaking out.
There are plenty of flights between ATH and CHQ. And worst case they could still put you on a flight to HER.

If they end up denying boarding, they'll have to (obviously) get you a new flight and pay 250 EUR (if I'm not mistaken).
Did you check in on the early or on the late side?

Maybe some of the details filled in during purchase were incorrect? :D

The airline must first seek volunteers, and only if there aren’t enough would they be allowed to involuntarily deny boarding. Obviously the offer for voluntarily not taking the flight is likely to be less than the forced compensation.

If you are eventually denied boarding then Article 4 of EC261 applies, which mandates compensation under Article 7 plus duty of care. The compensation for that flight distance would be €250.

However, I suspect this is a glitch and it’s unlikely you’ll have a problem if you really want to be on that particular flight.

Just as an aside; Greek, which I assume is a language that MSPeconomist thinks that one cannot read, is read (and spoken) by millions of people...

An update: oversold

Waiting in line at the gate. They offered a later flight at the check-in counter.

Did they advise you of your rights under EC261, as they have to do? With the number of flights every day it’s often worth taking the €250, but make sure it’s paid in cash rather than being fobbed off with vouchers.

No, this not what I think that MSPeconomist was suggesting. I'm very well aware of both the use of "one" as a pronoun as well as of what was in her/his mind. Still, on behalf of a "minority" (there are only about 10 million Greeks in the world ;)), I am a bit fed up by suggestions, direct or indirect, that absolutely everything should be made available in English. After all, there are more native Spanish speakers (even in the US!) and I've never heard a Colombian/Spaniard/etc. suggesting anything of the kind. In this particular case the comment about a language that one can read was completely unnecessary: had MSPeconomist googled "Olympic Airways" and "Conditions of Carriage" (s)he would have found this page, which is the second one to be returned by the specific search :)

What happened in the end? It's happened to me in the past, that they were looking for volunteers (desperately) at the gate, to depart 2 days later (no other flight in between) and get 500 euro (and all paid hotels etc.). In the end, a pax.-crew staff of other airline offered to travel jumpseat, captain accepted and issue was resolved.

Ended up queueing for the front desk, they gave me a bp with 28a and there was a long line behind me