Hi
This is copied from the F1 help
0 Digit (0 through 9, entry required; plus [+] and minus [-] signs not
allowed).
9 Digit or space (entry not required; plus and minus signs not allowed).
# Digit or space (entry not required; blank positions converted to spaces,
plus and minus signs allowed).
L Letter (A through Z, entry required).
? Letter (A through Z, entry optional).
A Letter or digit (entry required).
a Letter or digit (entry optional).
& Any character or a space (entry required).
C Any character or a space (entry optional).
.. , : ; - / Decimal placeholder and thousands, date, and time separators.
(The actual character used depends on the regional settings specified in
Microsoft Windows Control Panel.)
< Causes all characters that follow to be converted to lowercase.
Causes all characters that follow to be converted to uppercase.
! Causes the input mask to display from right to left, rather than from left
to right. Characters typed into the mask always fill it from left to right.
You can include the exclamation point anywhere in the input mask.
\ Causes the character that follows to be displayed as a literal character.
Used to display any of the characters listed in this table as literal
characters (for example, \A is displayed as just A).
Password Setting the InputMask property to the word Password creates a
password entry text box. Any character typed in the text box is stored as the
character but is displayed as an asterisk (*).