What is a graduated pension?

If you were working between April 1961 and April 1975, you may have built up rights to a second state pension called a graduated pension.  It is unlikely to be very big, but will be included in a pension forecast. For every £7.50 (man) or £9 (woman) of graduated contributions paid you get 10.20 pence (in 2006/07).

There's a bit more here on the Pension Service website.