Becky Sullivan

A single four-letter word — added to a provision of the tax code — has professional sports leagues scrambling, as teams face what could be millions of dollars in new taxes.

"Real."

The revision changed a section of the tax code that applies to "like-kind exchanges." Under the old law, farmers, manufacturers and other businesses could swap certain "property" assets — such as trucks and machinery — without immediately paying taxes on the difference in value.