Correct usage is ...

  showmain  pdb_code template  [-l ligand/chain/E.C. no]  [-f output_file]
            [-option option]  [{-i | -I} include_file]  [-c call-no]
            [-e]  [-enzymes]  [-profunc]  [-highlights]  [-u user-id]
            [-s start-no]  [-code security-code]  [-dir dirname]
            [UPLOAD | MCSG]  [-wkdir working_dir]  [-score score]
            [-EBI]  [-par1 parameter1] [-par2 parameter2]  ... 
            [-par10 parameter10] [-drat] [-drugport] [-sas] [-chain chain_id]
            [-drug_id DBref] [-uniprot_acc UniProt]
            [-db database_dat]  [-tdir template_dir]  [-trdir template_real_dir]
            [-ligsearch]  [-ligand_ranges ranges]  [-prop]  [-ligplus]  [-disastr]  [-varsite]
            [-pdbsum1]  [-relinks]
 where
   * pdb_code        = PDB entry to be displayed
   * template        = Name of template page to be displayed
   * -l chain/ligand/E.C. no  = chain/ligand/E.C. number to be shown
   * -f output_file  = write output to given file rather than to standard
                       output
   * -option option  = switch on appropriate OPTION_XXXX block in the template
                       file
   * -i include_file = file to be included at the #include line
   * -I include_file = full path and filename of file to be included at
                       the #include line
   * -c call number, indicating which menu item has been called and should be
                       highlighted
   * -s start number, indicating which start number for given group of items
   * -e              = have error in PDB code
   * -enzymes        = pages are for Enzyme Structures Database
   * -parN parameter N = additional parameters, numbered 1-10
   * -profunc        = pages are for ProFunc
   * -highlights     = PDBsum highlights page
   * -u user-id      = Identifier for temporary data dir
   * -code security-code = Password for secure entries
   * -dir dirname    = Name of temporary working directory
   * UPLOAD          = Uploaded PDB file for PDBsum generation
   * MCSG            = MCSG structure
   * -wkdir working_dir = Name of working directory
   * -score score    = Score required to be passed to some pages
   * -EBI            = Flag indicating that called from EBI PDBsum page
   * -drat           = Flag indicating that called from DraT DB
   * -drugport       = Flag indicating that called from DrugPort
   * -sas            = Flag indicating that called from SAS
   * -chain chain_id = PDB chain identifier
   * -drug_id        = DrugBank id for DrugPort drug page
   * -uniprot_acc    = UniProt accession for DrugPort target page
   * -db database_dat = Name and path of database.dat file to be read in at start
   * -trdir template_dir = Real directory where HTML templates are to be found
   * -tdir template_dir = Equivalent logical name
   * -ligsearch      = pages are for LigSearch
   * -ligand_ranges ranges = Ligands selected on ligand clusters page
   * -prop           = proprietary installation of PDBsum
   * -ligplus        = pages are for LigPlus licence system
   * -disastr        = pages are for DisaStr
   * -varsite        = pages are for VarSite
   * -list           = list fields (for debugging)
   * -pdbsum1        = Standalone version of PDBsum
   * -relinks        = Make all image links relative