What is bombing g.g. ?

I’ve come across an RAF publication called “Ground Gen for Airmen” all about living in the RAF.

Was there such a thing as “bombing ground gen”?

GOOD JOB

Good ideas, thanks.

Here is a look at the formation of his letters which have a descender.

I suspect they are both lower case letters.

If it is lower case letters maybe it isn’t Gee which I assume would have been written with an upper case G

Is there the possibility that the second letter could be a ‘j’ rather than a ‘g’?

For what it’s worth, ‘Good grouping’ also sounds very plausible to me. 

Or Good Grouping???

‘Gee gen’ would certainly make sense to me, as ‘gen’ was a frequently used term in those days……

 General knowledge concerning the use of using gee for navigating? ‘Gee gen’ ?

It is handwritten but it definitely looks like a double g

He says that he spent the day catching up on bombing g.g

If it’s handwritten, could you be misreading ‘bombing gee’???