The distance (in points i.e. 1/72 inches) that text should be moved away from its features. The distance is measured from the point symbol radius or line feature symbology edge. The distance is measured on the screen (i.e. not in the map) in points, comparable to the text font size.
This can be a negative value, to pull the label closer to the feature if, for example, the average size for a point symbol is overly conservative for the actual graphic shown.
If no value is set, then 1 point is assumed.