OK,
I've got this to partially work. See my first post above.
I've deleted the UK line in D008.dat
UK,United Kingdom,010000------------------
and I've left in my RAF line:
RA,RAF,0100001111--------------
As a result, all Brit Mil aircraft hex code 43C* now show the RAF "Flag" RA.BMP in the My Flights list.
However, as I've deleted the UK entry, I don't get a UK flag for British aircraft any more. It looks like the UK entry in the D008.dat file is overriding the Mil sub code. It might be that it's not possible to get down into country sub codes?
I'll play some more and report back :-)
Edit:
RB will only recognise the binary Mode S if it is 24 characters long, with the "wildcards" being represented by the appropriate numbers of "-"
The problem seems to be that RB is only looking for the first "match" then not looking any further, so when it finds:
010000
then it does not look any further so it does not see:
0100001111
The UK binary code is the only code in the list that starts 010000 so I suppose that once this has been found by RB, then it doesn't need to look any further - shame.
I'm still waiting for a response from AirNav Development and hopefully there will either be a way around this, or there will be a fix at a later date.
Although I'm not an expert, the SBS-1 seems to tell itself how many characters to look for in the binary code, and they only use 16 characters with "*" as the wildcard.
e.g.
010000**********,6
0100001111******,8
See the effect in the My Flights below - No UK flag, but the Mil aircraft is showing the RAF logo! Testing USAF too, see the KC135.