Use the Mask property to filter characters during data input.  Use the MaskChar property to change the masking character. If the Mask property is empty no filter is applied. The Mask property is composed by a combination of regular characters, literal escape characters, and masking characters. The Mask property can contain also alternative characters, or range rules. A literal escape character is preceded by a \ character, and it is used to display a character that is used in masking rules. Here's the list of all rules and masking characters:

Here's the list of all rules and masking characters.

• # (Digit), Masks a digit character, [0-9]
• x (Hexa Lower), Masks a lower case hexa character, [0-9],[a-f]
• X (Hexa Upper), Masks an upper case hexa character, [0-9],[A-F]
• A (AlphaNumeric), Masks a letter or a digit. [0-9], [a-z], [A-Z]
• ? (Alphabetic), Masks a letter. [a-z],[A-Z]
• < (Alphabetic lower), Masks a lower case letter. [a-z]
• > (Alphabetic upper), Masks an upper case letter. [A-Z]
• * (Any), Masks any combination of characters.
• \ (Literal Escape), Displays any masking characters. The following combinations are valid: \#,\x,\X,\A,\?,\<,\>,\\,\{,\[
• {nMin,nMax} (Range), Masks a number in a range. The nMin and nMax values should be numbers. For instance the mask {0,255} will mask any number between 0 and 255.
• [...] (Alternative), Masks any characters that are contained in the [] brackets. For instance, the [abcA-C] mask any character: a,b,c,A,B,C

The following sample shows how to mask an IP address:

Editor1.Mask = "{0,255}\.{0,255}\.{0,255}\.{0,255}"

The Mask property has effect for the following types: DropDown, Spin, Mask, Font, Button, PickEdit and LinkEdit.