CPU lettering/models/suffix/code
You'll also note that some CPUs have a letter at the end of the model name. Here is a guide to what they mean:
K: Unlocked for overclocking
H: High-performance graphics
T: Optimized for efficient desktop computing
U: Optimized for laptop power efficiency
F: High-performance processor used with discrete graphics cards (ex. Gaming)
X: Unlocked for extreme desktop performance