Here are the various connections based upon your images.
I have left the label spelling in the image provided the same as the image. They match any misspellings in the three images.
- "I don't know" marked inlet is a vacuum line. Your petcock has two lines coming off of it. The smaller one is for vacuum, the larger one is for fuel.
"Reservoir Fuel Supply" is actually a vacuum connector. The vacuum opens a diaphragm that allows fuel into the carburetors. This is a safety component in case your float is stuck open so your cylinder doesn't fill with fuel and create a hydro-lock situation which could be catastrophic to your engine.
"Main Fuel Suply" is correct and attaches to the carburetor fuel inlet from Image 2
"Vacuum" is incorrect. It is either a fuel tank vent hose or a drain. Either way it would connect to a hose that routes to the bottom of the motorcycle behind the engine and before the swing arm.
"Drain (I think...)" is possibly correct. As above, it is either a fuel tank breather or an overflow. One of the two. It routes the same as described above, behind the engine.
Carburetor Parts Explosion *
Fuel Tank Parts Explosion *
Images from Kawasaki via https://www.motorcyclespareparts.eu