Returns 0 (false) if container data was changed or deleted outside FileMaker; otherwise, returns 1 (true).
VerifyContainer ( field )field - any text, number, date, time, timestamp, or container field; or any text expression or numeric expression.
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FileMaker Pro 12.0
Returns a Boolean value representing the validity of data stored externally in a container field:
•0 (False) if files saved externally were modified or deleted.
•1 (True) if no changes or deletions occurred.
Returns ? if the specified field is not a container field.