maxScale

Labels will only be visible when the viewing scale is smaller than (or equal to) the maxScale. For example, if the viewing scale is 1:12000 and the LabelingInfo.maxScale is 1:10000, then the labels will be visible (because 1/12000 <= 1/10000).

A LabelingInfo.maxScale of 0, which is the default, indicates no upper limit on the viewing scale.