Joe,

>I've noticed various ways to use the CheckRuleHook.
>It seems that one might work better with child objects and the other with parent objects.
>Could someone help indicate what the idea behind each of the following syntaxes is and when whould each be used?

In one case, the business rule object is checking business rules for all rows, and in the other case it's checking the current row. The current row checking is suited for situations where you only allow the edit of a single DataRow at a time. The "all rows" checking is suited for situations where you allow users to change all rows in a DataTable.

Regards,