Regulations state the following (excerpt):
2.02 THE NET ASSEMBLY
2.02.01 The net assembly shall consist of the net, its suspension and the supporting posts, including the clamps attaching them to the table.
2.02.02 The net shall be suspended by a cord attached at each end to an upright post 15.25cm high, the outside limits of the post being 15.25cm outside the side line.
2.02.03 The top of the net, along its whole length, shall be 15.25cm above the playing surface.
2.02.04 The bottom of the net, along its whole length, shall be as close as possible to the playing surface and the ends of the net shall be as close as possible to the supporting posts.
Type net in the keyword search to get the full list but the ones above are linked to its placement.