TTChartOnGetSeriesMark

type TTChartOnGetSeriesMark = procedure(ASender: TObject; SeriesIndex, ValueIndex: Integer; Var MarkText: WideString) of object;

Type Library
TeeChartx

Description
This event notifies the user that a MarkText String must be supplied. MarkText string contains the default text representation. You can alter MarkText for the SeriesIndex to paint a customized mark.