Getting error while reading potential file

In potential file. If I want to know the meaning of all these parameters? say atom parameters, as given below:
! Nr of atoms; cov.r; valency;a.m;Rvdw;Evdw;gammaEEM;cov.r2;#
cov r3;Elp;Heat inc.;n.u.;n.u.;n.u.;n.u.
I have read reaxFF papers. I get the meaning like cov.r for sigma bond covalent radius etc. But when I look Bond parameters or some other valence angle, torsion angle parameters. There are still some missing terms, i.e., n.u. and some more. I couldn’t find meaning it in literature. where I can find it?

Thank you,

That is a question about the ReaxFF force field itself and thus something to ask the original ReaxFF authors.

Thanks a lot, Axel.

Have you also read the supporting information? “A full description of all ReaxFF potential functions can be found in Supporting Information” J. Phys. Chem. A, Vol. 112, No. 5, 2008

Thanks, Jones. I have read parameter file and functional form and compared with ReaxFF: A Reactive Force Field for Hydrocarbons J. Phys. Chem. A 2001, 105, 9396-9409 , ReaxFFSiO Reactive Force Field for Silicon and Silicon Oxide Systems J. Phys. Chem. A 2003, 107, 3803-3811. Just a few terms are missing.