1.  General.  In determining the adjusted gross income of a nonresident partner of any partnership, there must be included only that part derived from or connected with sources in this State of the partner's distributive share of items of partnership income, gain, loss and deduction entering into that nonresident partner's federal adjusted gross income, as that part is determined under regulations prescribed by the assessor in accordance with the general rules in section 5142.  

2.  Itemized deductions.  If a nonresident partner of any partnership elects to itemize deductions in determining that nonresident partner's tax liability to this State, the distributive share of partnership items of deduction from federal adjusted gross income for that nonresident partner must be attributed to that nonresident partner.  

3.  Special rules as to sources in this State.  In determining the sources of a nonresident partner's income, effect may not be given to a provision in the partnership agreement that:  

4.  Partner's modifications.  Any modification described in section 5122, subsection 1 and 2, which relates to an item of partnership income, gain, loss or deduction, shall be made in accordance with the partner's distributive share, for federal income tax purposes of the item to which the modification relates, but limited to the portion of such item derived from or connected with sources in this State.  

5.  Alternate methods.  The assessor may, on application, authorize or may require the use of such other methods of determining a nonresident partner's portion of partnership items derived from or connected with sources in this State, and the modifications related to those partnership items, as may be appropriate and equitable, on such terms and conditions as the assessor may require.  

6.  Application of rules for resident partners to nonresident partners.  A nonresident partner's distributive share of items of income, gain, loss or deduction shall be determined under section 5191, subsection 1. The character of partnership items for a nonresident partner shall be determined under section 5191, subsection 2. The effect of a special provision in a partnership agreement, other than a provision referred to in subsection 3, having as a principal purpose the avoidance or evasion of tax under this Part shall be determined under section 5191, subsection 3.