Let's not worry about the original publication which this is further to. This addendum runs to 118 pages on its own. It has chapters on general procedures such as what to do when there are problems associated with National Insurance numbers. It also covers special procedures such as what to do regarding pension payments for a former employee or their spouse if the employee is deceased.
There are rules for Payroll Giving, payments that can be made without payment of tax or NIC, holiday pay, payments to New Deal procedures and how tronc masters should operate.
There are also chapters on procedures which only affect National Insurance, special types of employees and various rules relating to expenses and benefits.
The above only represents a brief description of some of the things mentioned and it may well be that some items are meaningless to you. For example tronc masters are only relevant where staff receive tips or gratuities. However, the complexity and variety of procedures does give an insight into why so many businesses now use payroll outsourcing.