The P2 code is a modified version of the Frank code where the DC frequency term is in the middle of the pulse instead of at the beginning. The P2 code is only valid for even code orders (N = 2, 4, 6, 8...)
The default P2 code Code Order is N = 4.
The P2 code has N2 elements and is defined as:
i,j
Where i and j range from 1 to N. For example, the P2 code with N = 4, by taking phase value modulo 
is given by the following sequence:
4x4
The figure below shows the spectrum of a 10 us pulse using P2 Coded phase modulation, where N = 10.
