.pre file format documentation

Hello,

I am using getdp for a modal analysis of a motor stator and housing. Currently I have a model with first order tetrahedra and 24385 nodes. I need a mapping from Node Number (1 .. 24385) and DOF (one of {UX, UY, UZ, ROTX, ROTY, ROTZ}) to DOF number (1 .. 142278). I should be able to generate that mapping from the .pre file, but don't understand the format (Appendix A.2.2 is no big help either). At least the number of all DOF (constrained and non-constrained) is

146310 = 6×24385 = 6×nnodes. Thank you in advance for your help.