For input field controls and selection box controls, this attribute specifies the Natural edit mask that is used to validate end user input. You can, however, only use an edit mask if you also use the Linked Variable option in the Attribute Source dialog box, which can be accessed by clicking on the STRING's Source button in the dialog element's Attributes window. When the dialog element loses the focus (the end user leaves the input-field), the content of the field is checked against the edit mask. If the input is not compatible with the edit mask, Natural displays a message box asking the end user to Retry or Cancel. For more information, please refer to the article Validating Input in a Dialog Element.

For list view columns, this attribute specifies the Natural edit mask used to format the values for the items within the column for display. Note that these values are stored internally in the format determined by the column's FORMAT attribute. Note that the primary column in a list view displays the item labels, so an edit mask applied to this column also determines the display format for the labels (even if the list view control is not in report view mode). For more information, please refer to the article Working with List View Controls.

For tree view items, this attribute specifies the Natural edit mask used to format the item's label for display. Note that the values is stored internally in the format determined by the item's FORMAT attribute. For more information, please refer to the article Working with Tree View Controls.

For date and time picker controls, this attribute specifies a custom format string used to format the control's contents. Note, however, that the format string does not conform to the Natural edit mask syntax. Instead, the control uses its own format specifiers, as documented in the article Working with Date and Time Picker (DTP) Controls.

Applies to	Date/time picker control, input field control, list view column, selection box control, tree view item.
Data Type	A253
Default Value	Empty string
Possible Values	Empty string / any Natural edit mask