This excerpt taken from the TEG DEF 14A filed Apr 5, 2007.
Section 5.07. Prior Plan Stock Unit Account.
(a) Limited Purpose Account. The Prior Plan Stock Unit Account is limited to Integrys Stock Units credited to a Participant under the Plan (or a predecessor plan) through June 30, 2001, together with such additional Integrys Stock Units as are credited in accordance with subsection (b) below based on deemed dividends on such Integrys Stock Units.
(b) Dividend Credits. Any dividends that would have been payable on the Integrys Stock Units credited to a Participants Prior Plan Stock Unit Account had such Units been actual shares of Integrys Stock shall be converted, for record keeping purposes, into whole and fractional Integrys Stock Units, with fractional units calculated to four decimal places, and shall be credited to the Prior Plan Stock Unit Account, based on the closing price of a share of Integrys Stock on the dividend date.