Personal code is so... personal indeed.
I have developed my set of rules in early years of IL2 that included, for example, no shooting at paratroopers and at those who landed with lights on or smoking . Quite often I used to stop my attack when I saw my opponent to be badly damaged and still flying. Especially the bomber. I'd salute, wish him safe landing and fly away. Avoided uneven dog fights where several friendly attacked one enemy at once. Etc, etc.
But personal it was, so I didn't complain when others treated me in different way.
In later years I have discovered new fun: just to fly and to survive in one mission as long as possible avoiding temptation of easy kills. P-38 with 100% fuel + tanks roaming just below contrail altitude over swarms of late 109s or Raidens... ah, that was cool.