here is the full text of IRS instruction: Item M
If you have contributed property with a built-in gain or loss during the tax year, the partnership will check the “Yes” box. Also, the partnership will attach a statement showing the property contributed, the date of the contribution, and the amount of any built-in gain or loss. A built-in gain or loss is the difference between the fair market value of the property and your adjusted basis in the property at the time it was contributed to the partnership. If you contributed more than 10 properties on a single date during the tax year, the statement may instead show the number of properties contributed on that date, the total amount of built-in gain, and the total amount of built-in loss.
The partnership is providing this for your information. Contributions of property with a built-in gain or loss could affect a partner's tax liability (in matters concerning precontribution gain or loss, and distributions subject to section 737), and may also affect how the partnership allocated certain items on your Schedule K-1. For information on precontribution gain or loss, see the instructions for box 20, code W. For information on distributions subject to section 737, see the instructions for box 19, code B.
