Fifé, Fédéral Internationale Féline, has made a system to easy identify cats by codes. EMS stands for Easy Mind System, and all cats registered in Fife will have EMS codes, that will identify the cats breed, color and pattern.

You can click here to go to Fifé´s own page about EMS codes.

An EMS code starts with three capital letters. These identify the breed. For Maine Coon, these letters are MCO.

The colors are in lower case letters. The first letter will each stand for the primary color of the cat. 

n - black
a - blue
d - red
e - creme
f - black tortie
g - blue tortie 
w - white

If the cat is carrying silver, there will be an "s" behind the color-letter. 

The amount on white is recognized with numbers behind the lower case letters.

01 - van
02 - harlequin
03 - bicolour
09 - any other amount of white

Then the following numbers is the pattern of the coat. 

11 - shaded
12 - shell
21 - unspecified tabby
22 - blotched tabby
23 - mackerel tabby
24 - spotted tabby
25 - ticked tabby


You can also find codes for eye-color. I have not seen them used much before, but I will add them anyway:

61 = Blue eyed
62 = Orange eyed
63 = Odd eyed
64 = Green eyed

I hope this list will help you understand EMS codes a bit more. EMS codes are mostly used in shows and breeding, but maybe you will find it interesting anyway.