Any characters, punctuation marks, and spaces can be used as dead characters. Dead characters are displayed during data entry, but they are skipped over by the insertion point and are not entered as part of the data.
The characters you want to use as dead characters are placed before, after, and between placeholders. They are displayed during data entry to make it easier for the user to enter formatted data such as telephone numbers.
The phone number entry filter (&9(###) ###-####) uses parentheses, a space, and a dash as dead characters. After you enter a digit immediately preceding a dead character, the insertion point moves directly to the first character after the dead character.