B/(W)
From ACT Wiki
Better / (Worse).
A label in financial reporting to indicate whether positive differences are good news - also known as 'favourable', or more simply better.
When the label is B/(W) the positive numbers are better than budget or prior period.
Under this convention, negative numbers are unfavourable, also known as 'adverse'.
When the label is (B)/W the opposite applies - negative numbers would be better and favourable.
Under (B)/W positive numbers are worse and adverse.