Use the Edit Hanging Character Class dialog box (Edit > Hanging Characters > New > Class) to specify the characters to be included in a hanging character class, the hang percentage of the class, and whether the class is leading or trailing.

The Edit Hanging Character Class dialog box

Enter characters in the Characters pane. Then choose a percentage from the Hang drop-down menu. The hang percentage specifies what percentage of the glyph width should always hang over the margin or what percentage of the glyph width should always indent. For example, if you choose –50%, the characters in the character class indent inside of the margin by half of their glyph width. If you choose 100%, the characters in the character class hang outside of the margin by their full glyph width.

Next, choose whether the character class is Leading or Trailing. Characters in a Leading class hang over the beginning margin. Characters in a Trailing class hang over the end margin.