Dell 5820 Memory Matrix

Greetings

In the 5820's manual there is a memory matrix here:

https://www.dell.com/support/manuals/en-us/oth-xlt5820/Precision_5820_OM_pub/memory-configuration?guid=guid-ce1561c8-88a9-45e3-bc3b-762cbb37e073&lang=en-us

There are no definitions for the abbreviations used in the table see image below:

what do the circled items mean?

Configuration?

SKL-W  (sky Lake - w series xeon?)

CLX-W

SKL-X

XLX-X

DPC

etc

Dells glossary of terms leaves something to be desired.

Sincerely Paul