This standard functionality is available in a number of screens including Basic Budget Entry/Account Details and Import Budget Assumptions.

By checking the "Exclude" box, the data on that row is not included in calculations for the Total.

This functionality can be used to include additional information to support calculations as well as remark lines.

In the below example, row 2 is excluded.  Please note that the total for the Account Number is $150.  If row 2 was not excluded the total would be $250 ($150 + $100).