Source Material Question

Hi,

I was hoping one of the moderators may be able to clarify a statement made in the W&B PIP guide 'Personal Independence Payment (PIP) Claims and Reviews on Physical Health, Mental Health and Learning Difficulties Grounds'

I am currently going through appeal and when discussing variable illness, the guide says:

Guidance issued by the DWP clarifies this by explaining that:
‘If a descriptor applies at any point during a 24 hour period, it is considered to apply for the entire day, whereas in DLA it would have to apply for ‘the majority of the day’ in order to apply.’

Could someone direct me to where this guidance is published or issued, as I would like to quote the document directly in my appeal papers.

Thank-you in advance.