The meaning of Kill marks?
 

http://pigboats.com/subs/199con4.jpg

So, as far as I know:

Rising Sun - Military Ship Sunk
Meatball - Supply Ship Sunk?
Pennant - Merchant Ship Sunk?

I'd gather the Airplane means Aircraft shot down. (duh)

But what are the "half flags" - Damage dealt but not sunk? Unconfirmed sinking?

Also, I have seen in addition to these flags, one that is a red circle with a white center on a white field. I think it was used WITH these two flags, but might not have been. Any idea what it might have represented?

Unfortunately I can't seem to find that image at the moment....

And I have seen this:

http://th03.deviantart.net/fs71/200H...12-d4b9k5q.png
used to show Pilots rescued...

Lastly - was this more or less standardized or did it vary from boat to boat?

While there were no standard, fleet wide, set of icons, the following were generally followed:

Stars - Number of war patrols
Japanese national flag - Merchant ships sunk
Rising sun flag (Japanese Naval ensign) - Number of military ships sunk
Partial flag Damaged ships

Like this?

http://donmac.org/Storage/seacatBF.jpg

There was really no standardization of the symbols used. It is likely this red circle designated a damaged merchant.

There are other submarines that used the "diagonal cut" icon to designate ships damaged and other submarines super-imposed a small "D" on the icon to designate ships damaged. It really depended on the individual ship or perhaps unit. The USS Barb also used the "filled in circle" to mean sunk and the "hollow circle" to mean damaged.

Pity this wasn't made a part of the game, auto adding marks for your sinkings... At least in sh4.

According to the pilot of an RAAF bomber (he didn't fly the plane in WWII, only at airshows) I once spoke to:

Rising Sun = Destroyed Warship

Ordinary Flag = Destroyed Merchant/Troopship

Half flag = Damaged

But of course, that's just what the RAAF did.

Sounds like a concensus, just leaving the pennants as a mystery. By which I mean they triangle flags.

Maybe they were for junks an fishing boats? :yep:

I believe this is so. Small craft, say less than 500 tons, were probably in a different category.

Some boats used different icons for the smaller patrol craft, since generally they were not counted as tonnage sunk.