What was the British Air Ministry specification or contract 38627/39 and what aircraft resulted from it?

[Sid Guttridge]

I understand 38627/39 was something related to light aircraft, because the Auster was reportedly a consequence of it.
When, precisely, in 1939 was 38627/39 issued?
And who, apart from Taylorcraft/Auster, responded to it and with what offerings?

Many thanks for any assistance.

Sid.