To specify values for a Clear transform:
Verify that the type of the transform that is selected in the mapping routine area is Clear.
In the Properties view, select the General tab.
In the General tab:
Click Clear with spaces if you want each character position in the string to be set to a blank space character (0x40).
Click Clear with low values if you want each character position in the string to be set to a LOW-VALUE character (0x00).
At runtime:
The runtime environment sets each character position in the string to the specified character. The length of the string is unchanged.