This excerpt taken from the ALL DEF 14A filed Apr 2, 2007.
ARP and SRIP
The first plan is the Allstate Retirement Plan (ARP), which is a tax qualified defined benefit pension plan available to all of our regular full-time and regular part-time employees who meet certain age and service requirements. The purpose of the ARP is to provide an assured retirement income related to an employee's level of compensation and length of service at no cost to the employee. This benefit can supplement other sources of income such as our 401(k) plan, social security, personal savings, and other assets. As the ARP is a tax qualified plan, federal tax law places limits on (1) the amount of an individual's compensation that can be used to calculate plan benefits and (2) the total amount of benefits payable to a participant under the plan on an annual basis. These limits may result in a lower benefit under the ARP than would have been payable if the limits did not exist for certain of our employees. The second plan, the Allstate Insurance Company Supplemental Retirement Income Plan (SRIP), was created for the purpose of providing ARP-eligible employees whose compensation or benefit amount exceeds the federal limits with an additional defined benefit in an amount equal to what would have been payable under the ARP if the federal limits described above did not exist.