This means "did the buyer take any of the debt associated with the property" such as back taxes, liens, past due interest (if the mortgage was assumed), etc.
Many times the buyer will agree to take the property without asking the owner to clear it of liens or back taxes. This is done often in a short sale. When this happens, the IRS says this is income to the owner/seller because they essentially "made money" by not having to pay the taxes, liens etc.