New beam design rules may be added to the table using the "New" button:
The "New" button will generate a new row in the table. The user may name and modify this new definition as described in Modifying Rules.
When a new rule is created and modified, it will not be permanently added to the project until saved using the "Save Changes" button. Closing the menu before saving will cause the new rule to be discarded.
A newly added beam design rule does not have any influence over the behavior of beam calculations until it is manually applied to specific elements by the user (refer to Applying Rules to Elements).