[AccessD] Identify Validation Rules in Access 2007

I'm trying to help someone remotely with an Access 2007 issue. I don't have
2007. He is running an Append query, but is getting Validation rule error.
All records destined for the Append are rejected.

He is unfamiliar with the original table, and Access generally.

He has 2 tables. A is his master table. B is the table with records to be
appended to A, if they don't already exist in A.

Field types in both tables match.

Is there a way programmatically, or some other way, to identify what the
validation rule is/are?

jack