Form AN 'proof of living in the UK..' question

[recort]

I phoned up the homeoffice yesterday to ask about clarification on the requested evidence listed on my online form print out - most items are clear but then it asks for: 'Proof of living in the UK for..' - I asked the lady and explained that I have done the last 6 years already for my PR card, which is why I am now officially allowed to ask for citizenship in the first place, but she said it was another process and therefore I have to document everthing for the 6 years again - can that be true?
if yes, can anyone explain to me where this 'proof of..' is acually explained (I can't seem to find a links in the gov.uk An-booklet - the PR guidance was pretty clear though, so I wonder, would it be that again)?
thank you

[CR001]

Citizenship laws are completely separate to EU rules and you will need to provide evidence as required to prove your residence due to your passport not being stamped when you exit/enter the UK and is a completely separate requirement to any previous HO applications.

Citizenship is based on 5 years not 6 years.