What is tax form SA2002, in the UK

I am trying to rent a place in London. After providing so many forms the realtor is now asking for SA2002. I have tried searching for this but cannot find out what it is. The realtor has the attitude that I should know. I have been living in the USA for the past 20 years. This year is the first time I filed a tax return since, forever. So, What is the form SA2002?