There are two review forms for PIP - AR1 Review Form and the AR2 Light Touch Review Form. The Light Touch Review is much shorter and is mainly for claimants with an ongoing award with no fixed end date and for claimants who are over state pension age. You can read details of the AR2 on page 137 of the Guide to PIP Claims and Reviews. benefitsandwork.co.uk/guides-for-claimants/pip
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems