Order of a projective plane

Definition
Let $$\pi$$ be a projective plane. The order of $$\pi$$ is defined in the following equivalent ways:


 * 1) For any point of $$\pi$$, it is one less than the number of lines through the point.
 * 2) For any line of $$\pi$$, it is one less than the number of points on the line.

The prime power conjecture states that the order of a projective plane, if finite, must be a prime power.