Creo Layout > Using Annotations > Notes and Symbols > About Notes and Symbols
  
About Notes and Symbols
You can insert notes and symbols into a layout to add information and detail a design for 3D design development. You can insert notes with or without leader lines, as well as add custom symbols or symbols from the symbol palette.
Set the file path of the user-defined symbol library using the layout_symbol_dir configuration option. Set the file path of the symbol palette using the layout_symbol_inst_palette configuration option.