This is where they are declared (I think):
COMMON /COMFIG/ NL,NLS,NIND,NA,MODX,MODY,MODZ,APC(NLMAX),
+ NABUR(NLMAX),LATTICE,XPOS(NABURMAX,NLMAX),YPOS(NABURMAX,NLMAX),
+ DUNIT, XUNIT, YUNIT, ZPOS(NLMAX)
I never programmed in Fortran, all I've learnt is from searching for errors...