You can select to use an alternate abbreviation field expression for labels that cannot be drawn, because they overlap other labels or do not fit within a region. Labels may overlap and not draw when zooming out of a map. Using abbreviations ensures that your points, lines, and regions have labels as you change the map zoom. You can either reference a column of short text or use a MapBasic expression to clip or shorten a column of label text.
The use of abbreviations gives you more control over how your map is labeled. Some examples would be using two letter codes for the region names within a country, route numbers for road names that cannot be drawn, or symbols for landmark names that cannot be drawn.