I did look up The British Nationality (General) (Amendment No. 3) Regulations 2015, and it lists 4 types of certifications ("forms" of "information"):
It lists residence documents and permits endorsed by ILR, but post 2000."(a)a permanent residence card,
(b)a document certifying permanent residence,
(c)a residence document issued under the Immigration (European Economic Area) Regulations 2000 which is endorsed under the immigration rules to show permission to remain in the United Kingdom indefinitely, or
(d)a residence permit issued under the Immigration (European Economic Area) Regulations 2000 which is endorsed under the immigration rules to show permission to remain in the United Kingdom indefinitely.”."
What about EEA citizens with ILRs or other certifications proving settled status issued before the October of 2000?
Were they forgotten, or were those settled rights not derived by EU rights or EC Act rights?
If they were forgotten, do they really need to request a DCPR now, to fulfil the AN requirements?