diff --git a/src/blc_program.cpp b/src/blc_program.cpp
index 9c97ebb54c85aff6a2960d3d42f785999a183bc1..84284205722d163d671999bce42afeb5a640bb5f 100644
--- a/src/blc_program.cpp
+++ b/src/blc_program.cpp
@@ -101,10 +101,12 @@ void blc_program_add_parameter(char const**result, char const *name, int require
 {
     Program_parameter parameter;
     
+    if (required!=0 && required!=1) EXIT_ON_ERROR("You can only have '0' or '1' required parameter but you have '%d'", required);
+    
     parameter.type=STRING;
     parameter.string_pt=result;
     parameter.name=name;
-    parameter.required_nb=(required!=0); //At this moment only binary choices are possible
+    parameter.required_nb=required; //At this moment only binary choices are possible
     parameter.help=help;
     parameter.default_value=default_value;
     
@@ -343,9 +345,9 @@ static void blc_program_interpret_parameters(int *argc, char **argv[]){
                             else EXIT_ON_SYSTEM_ERROR("Reading input for parameter");
                         }
                         tmp_parameter[parameter_read-1]=0;//Remove the last return;
+                        APPEND_ITEM(program_parameter.string_list_pt, &list_parameters_nb, &tmp_parameter);
                         linecap=0;
                         tmp_parameter=nullptr;
-                        APPEND_ITEM(program_parameter.string_list_pt, &list_parameters_nb, tmp_parameter);
                         fprintf(stderr, "Parameters '%s' %ld\n", tmp_parameter, parameter_read );
                     }
                     while(parameter_read>0);
@@ -358,7 +360,6 @@ static void blc_program_interpret_parameters(int *argc, char **argv[]){
                         (*argv)++;
                     }
                 }
-                
                 tmp_parameter=nullptr;
                 APPEND_ITEM(program_parameter.string_list_pt, &list_parameters_nb, &tmp_parameter);
                 break;
@@ -405,10 +406,28 @@ void blc_program_args_display_help()
     
     for(auto const &parameter : program_parameters)
     {
+        if (parameter.type==STRING){
+
         if (parameter.required_nb==0) fprintf(stderr, " [%s]", parameter.name);
-        else if (parameter.required_nb==-1) fprintf(stderr, " %s ...", parameter.name);
         else if (parameter.required_nb==1) fprintf(stderr, " %s", parameter.name);
-        else FOR(i, parameter.required_nb) fprintf(stderr, " %s%d", parameter.name, i+1);
+        }
+        else
+        if (parameter.type==STRING_LIST){
+                if (parameter.required_nb==0) fprintf(stderr, " [%s ...]", parameter.name);
+                else if (parameter.required_nb > 0) {
+                    FOR(i, parameter.required_nb){
+                        fprintf(stderr, " %s", parameter.name);
+                    }
+                }
+                else if (parameter.required_nb < 0){
+                    FOR(i, -parameter.required_nb){
+                        fprintf(stderr, " %s", parameter.name);
+                    }
+                    fprintf(stderr, "[%s ...]", parameter.name);
+                }
+        }
+        
+        
         
         option_length_max=MAX(option_length_max, (int)strlen(parameter.name));
     }