Vielen Dank.
Meine Vermutung stimmte doch ...
   char *lance_type =
# ifdef PAMs_INTERN
# define __ifname "ple"
   "PAMs EMega/VME"
# else
# ifdef MEGA_STE
# define __ifname "rle"
   "RIEBL VME (MSTE)"
# else
# ifdef ATARI_TT
# define __ifname "rle"
   "RIEBL VME (TT)"
# else
# ifdef SPECIAL
# define __ifname "rle"
   "RIEBL MEGA ST (mod.)"
# else
# ifdef MEGA_ST
# define __ifname "rle"
   "RIEBL MEGA ST"