Available vs Waiting Cargo?

[Quinch]

Just a quick question - what's the difference in sorting stations by Available Waiting Cargo and Total Waiting Cargo?

[skc]

"Total waiting cargo" is all cargo at a station that it not loaded into a vehicle.
"Available cargo" is the cargo at a station that is not yet allocated to be loaded into a vehicle.

Vehicles are not able to load their total load capacity in an instant, hence the reason for both values being present.

[Quinch]

Got it - is there a way to sort stations by most single cargo? I.e. if there's a particular cargo waiting at a station that keeps accumulating?

[skc]

If you're running v14.0, there's a drop-down at the top of the station list window, which defaults to "All cargo types and no rating". That allows you to select/deselect which you want to see.
If you're still running v13.x, there's a row of industry icons that you select from instead.

In both cases, a left-click on a cargo type will set it to display just stations which have "supplied" that cargo recently.
If you CTRL+left-click (certainly on Windows & Linux, not sure if it's that or "Option" on a Mac), you will toggle the selected cargo on/off without affecting any of the others.

EDIT TO ADD: I don't believe there's a way to show all cargoes and to sort them how you're wanting where each waiting cargo type is checked. I don't see it as impossible to add this in.