Select Add L Class in the Model Definition menu.
      　　　　

       Alternatively, within the model definition, right-click and select Add L Class.
     

      The L class addition screen will be displayed.
      Enter the large classification name in the L class name (here, it is the application layer)
      

       There are two types of element names: fixed names and arbitrary names.
      The application layer includes HTTP, SMTP, POP3, etc.
      If you want a fixed name, set HTTP, SMTP, POP3, etc.
      

       If you want to give it an arbitrary name, click the Arbitrary setting button.
      

      To revert to the fixed name, click Release Any. If you specify Optional,
     each person in charge will be assigned to the application layer in the instance
     (actual example). For that, set HTTP, SMTP, etc. In other words, arbitrarily,
     there are multiple classified items, and they are added during the work process.
     Specify if If there are multiple things to classify and it is known in advance,
     It depends on the person's way of thinking whether to write the element name
     fixedly or -- arbitrary --.

     Here, select "--arbitary--"
     

       Click the Add button to add the L class.