As mentioned, I use the flat ones for directional lights. The squared ones for the lamp type lights.
I found out, that it seems at the factory they didnt much care how they wired the lights in my camper. Meaning its a 50-50******shoot as to which part of the plug is + and which is -. SO on some of my LED's I had to remove the base, cris-cross the leads (and heat shrink one of them) and put the base back on for them to work.
It may take you a day or two to get used to the new lighting colour.