AR2 Form

Is it the AR2 form I will be sent when asked to renew my pip next year. Was awarded Pip at tribunal for 10 years, stating on both daily living and mobility that it is inappropriate to fix a term.
Tribunal no longer have any records of this, but I do have copy of tribunal award. Would it be helpful to send this Tribunal outcome with need to renew PIP. Tribunal outcome says how it relied on what I said and what was in bundle to reach decision when award originally made. If AR2 form do I need to send much medical evidence post award or can I just say "no change" on form. Is it right if AR1 form I would have to give more evidence. Am age 67, in receipt of state pension so is it AR2 form I will be sent. Bit confused re who is sent AR1 form and who is sent AR2 form, and whether can just be brief on AR2 form or not

Thank you