Use the Included Text Marker field to specify the characters that precede each line of an included text message. The default value is "> ". This puts the right-arrow character at the start of the included message when you choose Indented from the compose window Include menu. Tabs are not accepted as an indent character (but spaces are). Figure 4-36 shows the Compose window with an included message indented with ">".
The right angle bracket is at the start of the included message when you select Reply to Sender, Include or Reply to All, or Include from the compose menu in the Header window.