Well, sorry if it's wrong on some of them. The best thing is to look at your machine and see where the last little loop for the thread to go through before it goes into the needle. That will tell you which side it is to be threaded from.
I thought the chart was good for knowing which needles some of the machines need, because from what I understand, they don't all take the same ones. Mine all do, so that's good for me.