Use DisplayValues to specify strings the field uses to represent Boolean values. Use any pair of phrases, separated by a semicolon. For example, to have the true and false values correspond to the letters T and F, respectively, set DisplayValues as follows: 

On Windows:

Table1LogicalField.DisplayValues := 'T;F';

On cross-platform:

ClientDataSet1LogicalField.DisplayValues := 'T;F';

On Windows:

Table1LogicalField->DisplayValues = "T;F";

On cross-platform:

ClientDataSet1LogicalField->DisplayValues = "T;F";

Similarly, to set the values of true and false to the strings Yes and No, set DisplayValues to: 

On Windows:

Table1LogicalField.DisplayValues := 'Yes;No';

On cross-platform:

ClientDataSet1LogicalField.DisplayValues := 'Yes;No';

On Windows:

Table1LogicalField ->DisplayValues = "Yes;No";

On cross-platform:

ClientDataSet1LogicalField ->DisplayValues = "Yes;No";

The string associated with true or false can be an empty string. To set the value for true to an empty string, set DisplayValues to a string that begins with a semicolon. For example, to associate false with the string Fail, and true with an empty string, set DisplayValues to: 

On Windows:

Table1LogicalField.DisplayValues := ';Fail';

On cross-platform:

ClientDataSet1LogicalField.DisplayValues := ';Fail';

On Windows:

Table1LogicalField ->DisplayValues = ";Fail";

On cross-platform:

ClientDataSet1LogicalField ->DisplayValues = ";Fail";

To associate false with an empty string, set DisplayValues to the string for true, with no semicolon at all. 

The strings associated with true and false by DisplayValues appear in data-aware controls when they display the data for a Boolean field. If one of the strings is an empty string, boolean values associated with that string appear blank in data-aware controls. 

These strings are also used when getting or setting the Boolean field's AsString property. 

AsString