Letters K and G after caliber on German/Dutch cannon projos

Several small-caliber cannon rounds in my collection have either the letter “K” or “G” printed on the projectile along with the caliber. For example:

35x228mm HE, Dutch (made for Germany??):
35G
HE
CTG DM 11
EMZ 79-6

27x145mm solid aluminum dummy, German:
27K
EX
DM 10
MW-86-9
Ch.Nr. ?14445

20x139mm break-up, Dutch (made for Germany??):
20K
DM78A1
MAN
LOS NWM-2-88-X

What do the letters “K” and “G” mean after the caliber? Is this strictly a German marking? Am I correct in thinking that the rounds with Dutch manufacturers are made for Germany, given that they have “DM” model numbers?

Thanks in advance for any input!

K means “Kanone” - German term
G means “Gun” - English term

German “DM” numbers are not only the proof for a German use. The DM numbers are used in international trade to show the manufacturing standard and the type of ammo (together with naming the caliber).

Thanks very much! That has bugged me for some time.