We know that the Federation, at least the high ranking officials and Starfleet, were aware of the Q as a species but also "De-Lancie-Q" in particular. The thing is, while Q was quite fascinated with humanity as a whole and Picard in particular, I find it hard to believe he didn't meddle in the affairs of other species as much.
Also, we can surmise that other species elsewhere in the galaxy, such as the El-Aurians (at least some of them) and the Borg (post Best of Both Worlds), knew Q as well.
So, my question is: how about the other Alpha/Beta quadrant powers such as the Romulans/Klingons/Ferengi/Cardassians/Breen? Had they directly encountered the Q or were they at least aware of them? By this I mean first-hand experience and not leaked reports etc, that could be attributed to misinformation and so on.
Canon but also expanded universe stories are acceptable.