Instructions provided show what to do to stack labels rather than display labels on one line. For example:
12345c0888J All Zone M
Open the Label Expression dialog box.
A. Right-click on the layer in ArcMap's Table of Contents and select Properties to display the Layer Properties dialog box. B. Select the Labels tab. C. Click the Expression button to the right of the Label Field to display the Label Expression dialog box.
Type the following in the Expression in between the fields:
Code: [STATE_NAME] &vbnewline& [POP90_SQMI]
Click the Verify button to display a sample of the stacked label and then click OK.
To display the newly created stacked labels in the data view, right-click on the layer in ArcMap's Table of Contents and select Label Features option.