Label classes can be used to restrict labels to certain features or to specify different label fields, symbols, scale ranges, label priorities, and sets of label placement options for different groups of labels. For example, for a roads layer, you could use a different text size to label different types of roads based on a field classifying roads by importance. You could also create a query to label only cities with a population greater than 1,000,000.
- Ensure Labeling is the active way of displaying the Contents pane.
- Select a feature layer or label class in the Contents pane, and open the Label Class pane.
- Rename the default label class by clicking on the Class tab and choosing Rename Label Class. If you'll have more than one label class, click , choose Create Label Class, and type a name for your new label class.
- Select the label class from the Class drop-down menu, and click the SQL Query tab.
- Build the query expression that identifies the subset of features you want to label.
Set scale ranges for label classes
Some labels are most useful within a given scale range. For example, on a city map, a label class of all street names might be useful up to some minimum scale. As you zoom out beyond that scale, the labels would become too crowded—or too small if there is a reference scale set—and you may prefer to display a label class that only shows major street names.
Setting a minimum scale for labels can improve the overall redraw performance of your map, making panning and zooming more responsive, as labels are only drawn within the scale range at which they're useful.
You can set the minimum and maximum scales in the Visibility Range group on the Labeling tab. If no scale is set, the labels will have the same scale range as the feature layer.