Quote Originally Posted by mongoled
and I found a CABNE0530RPMW
R and A are the same thing. thanks to ocdetective for this:

First Digit is either R through to X for Monday to Sunday or A through to G for same. M means mixed assembly lot.
P merely means Penang
3rd digit is the sequential batch of cores used in assembly - so if they are using the first batch for that day its an A second batch is B and so forth. M means the cores used in the assembly came from different batches.
The existence of a W for the 4th letter means mixing of wafer lots in the core fabrication was prohibited. Its absence means the wafer lots could be mixed when making a batch of cores.
0450 etc is self explanatory and is the week of assembly.