This is the General tab of the Markers page of the Graph Options dialog box. The settings in this tab affect every kind of marker.
Text Size: Enter the size of the text you wish to use for your markers here. The default is 10. You may enter a value from 6 to 99. The larger the number, the larger the text that is displayed.
Label Precision: Enter the number of significant digits you wish displayed in any measurements displayed in a marker. The default is 4.