I am being PFB and INSIST I know what this reading stage means

[OhChristFENTON]

Actually I swore I'd never ask this, but I've googled and can't find a definite answer.

DS1 had a letter home today saying they will be following the ORT etc, and we have assessed your child's reading ability and have put them on to stage 9a.

What I'm wondering is, is 9a the stage just before 10, or is 9a only just into the level 9's ?

so it might go 9a,9b,9c,9d then 10.
or does it go 9d,9c,9b,9a, then 10. ?

I think you are definitely getting yourself confused. Doesn't it mean the first book at stage 9?

There is stage 9a followed by 9b (so just beginning the level) roughly age 5-7 years equivalent

Corrected, as usual, by mrz .

Well it could well be the first book in stage 9 Iamnotminterested, that would be the sensible place to start.