If the engine has not just been running, and the oil is "settled," fill it to the full mark on the dip stick. It holds very little oil anyway, so it should have as much oil as possible without overfilling.
Around Christmas, I changed the oil, and let it drip a pretty good while, but then I went to work on something else on the tractor. While doing that work, I kicked the container out of the way (accidentally.) After a long period of time passed, probably around two hours, you would be surprised at the mess that was on the floor. Apparently, the amount of oil it will hold depends on how long a person is willing to let it drain. Perhaps this can account for SOME of the differences between how much the manual says it holds, and how much individuals seem to be able to put into it.