I've read in a few spots that the driver/spanker sails were only used on occasion. When it was not an "occasion" did they fly a square sail on the lower course of the mizzen?
There's often situations, usually while sailing "off the the wind" (broad-reach to running) that the driver might not be wanted because it'll make steering more work as it pushes the stern. (weather-helm)
Then there's situations when sailing "on the wind" (broad-reach to close-hauled) when you gotta have it, especially when sailing coast-wise, in bays and harbors, etc.
You'll often see in paintings the tack of the driver pulled up the mast a ways, that's "scandalizing" the sail to reduce it's area with out taking a reef. Another method of scandalizing that's more rare to see is dropping the peak of the gaff. You'll see that more on smallish, gaff headed fishing boats, like catboats and sloops, than on larger ships, mainly because their driver is usually brailed up against the mast and gaff when stowed and dropping the gaff that way would be a p.i.t.a..
There may sometimes be a sail set on the cross-jack, though it's a bit rare. A captain in a rush might have a spare sail hauled up, a bit like setting a stuns'l, but there's almost never a dedicated sail on that yard, and very often there aren't even foot-ropes on it. When the mizzens'l was a lateen, it's spar would have interfered with a sail set on the cro'jack, so a sail wasn't put there.
Into the 1700's, it was quite common for ships to not set a mizzen t'gallant. On many ships t'gallants and royals were set "flying," that is they were already attached to the spar and set from on deck, and brought down, spar and all when taken in. That includes "jack-yard tops'ls" such as commonly seen on schooners, like Baltimore Clippers. Again, much the way stuns'l are set.
While many ships, especially larger warships, had separate topmasts, t'gallant masts, and royal masts; many had t'gallant and royal masts combined in a single spar. Sometimes with, and sometimes without, cross-trees and trestle-trees segregating them. The royal section was usually referred to as the "pole" and the whole spar might be called the "t'gallant pole."
Then there's situations when sailing "on the wind" (broad-reach to close-hauled) when you gotta have it, especially when sailing coast-wise, in bays and harbors, etc.
You'll often see in paintings the tack of the driver pulled up the mast a ways, that's "scandalizing" the sail to reduce it's area with out taking a reef. Another method of scandalizing that's more rare to see is dropping the peak of the gaff. You'll see that more on smallish, gaff headed fishing boats, like catboats and sloops, than on larger ships, mainly because their driver is usually brailed up against the mast and gaff when stowed and dropping the gaff that way would be a p.i.t.a..
There may sometimes be a sail set on the cross-jack, though it's a bit rare. A captain in a rush might have a spare sail hauled up, a bit like setting a stuns'l, but there's almost never a dedicated sail on that yard, and very often there aren't even foot-ropes on it. When the mizzens'l was a lateen, it's spar would have interfered with a sail set on the cro'jack, so a sail wasn't put there.
Into the 1700's, it was quite common for ships to not set a mizzen t'gallant. On many ships t'gallants and royals were set "flying," that is they were already attached to the spar and set from on deck, and brought down, spar and all when taken in. That includes "jack-yard tops'ls" such as commonly seen on schooners, like Baltimore Clippers. Again, much the way stuns'l are set.
While many ships, especially larger warships, had separate topmasts, t'gallant masts, and royal masts; many had t'gallant and royal masts combined in a single spar. Sometimes with, and sometimes without, cross-trees and trestle-trees segregating them. The royal section was usually referred to as the "pole" and the whole spar might be called the "t'gallant pole."
Great answer, I liked that. I also "liked" that 
Thank you.
Thank you.
Another reason a larger ship wouldn't scandalize by drooping the gaff is, many ships braced their mizzen tops'l yard and cross-jack to the peak of the gaff.
James Lees says; "...up to 1805, [braces] led aft with the standing part made fast to the peak of the mizzen yard (lateen) or gaff, the running part rove through the brace pendant blocks, back through single blocks on a span round the mizzen yard or gaff, just below the standing part, and the brace led down to the rails by the transom....from 1805to 1815 the standing part of the brace was seized to the main mast head..."
What I can find in contemporary paintings and models conforms Lees, and the painting in your log is rigged to the driver gaff as well.
I am so glad I don't have to rig my Macedonian that way; I can only imagine what a rat's nest that would become on an RC boat.
James Lees says; "...up to 1805, [braces] led aft with the standing part made fast to the peak of the mizzen yard (lateen) or gaff, the running part rove through the brace pendant blocks, back through single blocks on a span round the mizzen yard or gaff, just below the standing part, and the brace led down to the rails by the transom....from 1805to 1815 the standing part of the brace was seized to the main mast head..."
What I can find in contemporary paintings and models conforms Lees, and the painting in your log is rigged to the driver gaff as well.
I am so glad I don't have to rig my Macedonian that way; I can only imagine what a rat's nest that would become on an RC boat.
Just another related question. Lees and Petersson do a great job of explaining that a rope goes from "A" to "B" but where does a person find out what that rope is for. Where can a person look to find answers like Jerry gave me? Standing rigging is not to tough to figure out but standing rigging(to me) is confusing.