If you are using a Win95 keyboard, open StyledEdit and hold down the left Win key while typing. You will see other characters appear (like the TM symbol, copyright symbol, etc.)
[Editor’s note: This key mapping applies to all BeOS applications that use the standard BeOS Text View, including BeMail, dialog boxes, etc. To see the special keys visually, open the Keymap preferences panel and press the Win key. -sfh]