Use of the term "Charlie Charlie"

[Richard Taylor]

QSY

I tend to hear Charlie Charlie on HF,as Truckmaster says.

What about the above phrase?

I used to hear QSY when pilots confirmed that they were "two-way" with their next sector.They were cleared to "QSY" en route.

Where does that terminology come from,& is it still used today(don't think I've heard it for some time now).

Thanks...I'll QSY to lunch now...