Thanks for the replies.
So we now know character 5 is not constant as I had incorrectly suggested. D or E in there so far.
So...
14 alphanumeric digits 08QDxxxx120yyy . Seemingly only characters 1234 & 9,10,11 are constant.
If anyone finds something to show the 08QD and 120 are not constant let us know and will revise.
That leaves xxxx and yyy
Characters reported as residing in positions so far from a fairly small sample:
x D or E
xx 9, A, B, C, 1
xxx 1,4,C,G,K,P,R,T,V
xxxx 0 or A
y 0, 1, 2
yy 1,A,G,L,M,P,R
yyy 6,7,8,9,A,T
Those of you with x = E have all reported xx as 1 which bodes well for these two representing year and month. I have one outlier but I am not confident I read the serial correctly from a screen grab.
So far my list of serials or part serials has
D9
D9
D9
DA
?A
?B
DB
DC
DC
E1
E1
E1
So possibly
x D = 2016 and E = 2017 build year.
xx = build Month where 9 = Sept, A = Oct, B = Nov and C = Dec then 1 = Jan
Just need some to show me a serial that does not math this schema for x and xx and will bin this theory.
Also if letting us know a partial serial let include if under the CE0890 label there is a trash can or a Avatel logo. That changed at some point recently too. My DC (maybe December) has it whilst my replaced D9 maybe (Sept build) did not.