From another source in the forum itself, this is an excerpt from the PPR mail received
" We require a valid passport for you and all accompanying family members. Passports must be submitted together. Each passport must be valid at least six months have at least two blank visa pages. If there are children included in your passport there must be two blank visa pages for them as well. Please note that a Confirmation of Permanent Residence (IMM 5688) and visa cannot be issued to holders of Diplomatic, Official or Military passports. You must obtain an ordinary passport."
There you go. You need to have a passport with validity of 6 months at the time of CoPR and must have two blank pages. But if you find out that there is something
amiss then please do let us know as well.
Goodluck with your application.