anchor.diff:  write(stderr,*)
   write(stderr,*) '-flt FLTFILE         Triangular source faults'
   write(stderr,*) '-sta STAFILE         Station/receiver locations'
  -write(stderr,*) '-trg TRGFILE         Target/receiver kinematics'
  +write(stderr,*) '-trg TRGFILE         Target/receiver geometry'
   write(stderr,*) '-haf HAFSPCFILE      Elastic half-space properties'
   write(stderr,*) '-disp DSPFILE        Displacement (E N Z)'
   write(stderr,*) '-strain STNFILE      Strain matrix (EE NN ZZ EN EZ NZ)'
   write(stderr,*) '-stress STSFILE      Stress matrix (EE NN ZZ EN EZ NZ)'
   write(stderr,*) '-estress ESTSFILE    Effective (maximum) shear stress'
   write(stderr,*) '-normal NORFILE      Normal traction on target faults (requires -trg)'
  -write(stderr,*) '-shear[max] SHRFILE  Shear traction on target faults (requires -trg)'
  +write(stderr,*) '-shear SHRFILE       Shear traction on target faults (requires -trg)'
   write(stderr,*) '-coul COULFILE       Coulomb stress on target faults (requires -trg)'
   write(stderr,*) '-geo|-xy             Use geographic (default) or cartesian coordinates'
   write(stderr,*)
  +write(stderr,*) 'See man page for details'
  +write(stderr,*)
   
   stop
   end subroutine usage
  
positive.code:                    iWantDisp, iWantStrain, iWantStress, iWantTraction, &
                     nstations, stations, targets, &
                     lame, shearmod
  use io, only: stderr, verbosity
  implicit none
  
  
negative.code:         endif
          ! Maximum (effective) shear stress: estress
          if (estress_file.ne.'') then
              call max_shear_stress(estress,stress)
              write(121,*) stations(iSta,:),estress
          endif
      endif
  