UPDATE: A Home Office source says that the update is a mistake, incredibly.

Form AN for applying to naturalise as a British citizen has just been updated to state that a permanent residence certificate or card is NOT mandatory for EEA nationals and their family members. It now says:

Please Note: Whilst the submission of a document certifying permanent residence or a permanent residence card is not mandatory, failure to submit one may lead to delays in reaching a decision on your application. If you do not provide a document certifying permanent residence or a permanent residence card then you must provide the following for consideration:

• Evidence of exercising Treaty Rights for 5 years for the relevant EEA national. This may include… [lists types of evidence]

The old version (June 2016) used to say on the same page:

SECTION 4 Evidence of settlement for applicants from Switzerland or the European Economic Area or their non-EEA direct family members see pages 10 to 11 of the Booklet AN

• Your valid passport or valid EEA national identity card as evidence of your nationality; And
• A permanent residence card issued by UKVI

Further information on how to apply for a permanent residence card and the current fee, can be found on the Gov.uk website, at this link…

I was not aware by any other means of a change of law or policy on this, which is very confusing and indeed confused. The update made it appear as if the change in November 2015 to require permanent residence certificates and cards to be provided by EEA nationals and their family members might have been reversed but a Home Office source has stated that the update is simply a mistake.

Source: Application to naturalise as a British citizen: form AN – Publications – GOV.UK