[marcoszorrilla]

Aquí tienes la información, pero en inglés, no tengo tiempo de traducirlo.

Update Rule

Database Desktop provides two update rules for tables that use referential integrity. Update rules specify what happens when a user tries to update or delete data in a parent table that has dependent records in a child table.

Prohibit

Prohibit specifies that you cannot change or delete a value in the parent's key if there are records that match the value in the child table.
For example, if the value 1356 exists in the Customer No field of Orders, you cannot change that value in the Customer No field of Customer. (You can change it in Customer only if you first delete or change all records in Orders that contain it). If, however, the value doesn't exist in any records of the child table, you can change the parent table.

Cascade

Cascade specifies that any change you make to the value in the key of the parent table is automatically made in the child table. If you delete a value in the key of the parent table, dependent records in the child table are also deleted. Cascade is the default update rule.
To cascade an update across tables, Database Desktop must place a lock on the target table. If the lock is denied (because another user has already placed a lock), Database Desktop cannot perform the cascade update.

If you are working with SQL tables, the availability of cascading updates and deletes varies according to the table type and software version.

Strict Referential Integrity

Choose Strict Referential Integrity to protect your data from being corrupted by earlier versions of Database Desktop (the default). Strict Referential Integrity specifies that Paradox for DOS cannot access a table on which you've defined referential integrity.
Suppose you use a version of Paradox for DOS to open a Paradox for Windows table that uses referential integrity. You could add data that violates the referential integrity, because the version of Paradox you're using doesn't recognize the referential integrity. To prevent versions of Paradox for DOS from opening the table, check the Strict Referential Integrity check box.

Un Saludo.