Carers Allowance, form DS700

Can anyone remember when it became a requirement for the cared for person to sign the DS700 form.

I very well remember the time before this requirement was added, I used to get quite a lot of calls from (usually retired) people to say that their Pension Credit and or Housing Benefit had drastically reduced and on investigation we commonly found that an adult son or daughter was being paid Carers Allowance. The addition of the extra sections in the form reduced this dramatically but I can’t quite remember when this change took place, from my recollections it was about 2007/8 but my memory is not that reliable!  There must have been some impetus for the change but I have not been able to find anything to suggest why it was changed, (did DWP get an influx of complaints?)

I know it was dropped around 2020 but my case in part depends on the reasonableness of DWP needing a signature on
a paper claim form and not on an electronic one around 2018.