Set default values for tags that return empty values
for example add "item_salary|Not Available" so if the tag named [item_salary] will return empty, it will return "Not Available" instead.
Adjust numeric tags values (increase/decrease/multiply)
for example add "item_price|item_price * 1.5" so if the tag named [item_price] will return 10, it will return 15 instead.

*for example add "item_price|item_price + 2" so if the tag named [item_price] will return 10, it will return 12 instead.