If memory serves [and it may not, my seaweed has withered and chrystal balls dropped off]
TAFs used words like GRADU, INTER, RAPID
whereas
TRENDS were just a three colour sequence eg BLU YLO AMB
I was Binbrook SMetO's boss as PMetO 1 Group Bawtry 1980-3 [I know ...... the Met organisation only fitted the RAF where it touched!]
So PMetO Bawtry had line management of Met. at:
Leeming, Linton, Church Fenton, Finningley, Binbrook, Scampton, Waddington, Cranwell, Cottesmore [not Wittering!], Wyton and Marham.
As a secondary duty he had oversight of the Distant Learning Met Programme.
Come to think of it, I was overworked and underpaid.