RA65 base - RA55 hkg
Lets see if I can unmuddy the waters;-)
Take a base after 1/1/08 - retirement age is 65. Stay in HKG on CoS99, RA55.
Now for the confusing bits. If you are on a base as of 31/12/07 you can stay on CoS99 or sign CoS08. But once on-shoring occurs, you will have to sign over to CoS08 or move back to HKG.
Even though there is no immediate legal imperative for it do so, CX is taking the position that all basings from 1/1/08 are with RA65 even though it might take another year or so to form the onshore company. Only those already on bases not wanting RA65 will be effected. They can stay on CoS99 till onshoring occurs....Apr08 for UK and sometime after for the rest.
For FOs in Australia, for example, if they can delay signing over to CoS08 till onshoring actually occurs, then they will be eligible to receive bypass pay subject to seniority whilst they remain on CoS99.
Hopefully clearer than mud;-/