I am installing a toilet flange in new construction and am confused as how it aligns. It has 2 slots roughly 2in long, on each side that go in a radius along with flange, it also starts out large and then narrows down. I believe I am to get the narrow ends of these slots parallel with the back wall. It also has 2 other small slots 90 degrees from the others, yet they run to the end of flange and are only half inch long. Let me know if my idea is correct.