So I've just purchased my third piece of Le Creuset, they've all been second hand finds (champagne taste, beer budget?)

So I was trying to identify it by markings in the lid and underneath the pot. It seems everyone has numbers. I have just a letter F. I'm stumped! Anyone know what this means? I did end up just measuring water and pouring it in, which gave me 5/5.5 Qt. It's "flame" coloured.

dont tell me that the F stands for FAKE! Haha