[TonyMadrid]

the C= decade; in this case 1960's
the 9 indicates th eyear; in this case 1969
the M indicates the vehicle model; i.e., a mustang, a galaxie,etc.
6015 is the part number

the remaining alpha/numerics usally indicate versions of the part that were manuafctured after the original manaufacture; This is something similar to computer software realeases such as Windows 3.0, 3.1, etc.

I am currently not home but I have acouple of books at home that I believe outline the exact data. Hang in there and I will check for the info when I get home.