Having conditional formatting and/or variable input masks at the table level
is not possible. However, when using a data entry form (and data entry
should almost never be done directly into a table), you can set either or
both format and input mask based on some other user criteria. For example,
if the related country address was US or Canada, the phone mask would be
"(xxx) xxx-xxxx", but if other then the mask would change to "xxxx (xxx)
xxx-xxxx". You would need to code this into the form's AfterUpdate event of
the country/zip control.
-Ed