- 0Apr 4, '09 by patfrombelairhi, i am interested in the lnc programs. just to make sure it was what i wanted, i bought the older edition of lnc principles and practice. i have read part of it and realized just how much the lnc has to know. is the lnc required to have the knowledge of all the material in that book? if so, not sure i am right for the field.