MLK = Mid Life Kicker Signifies a newer revision of the model or minor upgrades to the model specs. There isn't typically enough difference to change model name, but can add some additional functionality - maybe additional chassis options (more drives, more drive options, etc.), TPM, additional card/expansion options, NVMe options, etc.
I may just need more coffee or my glasses perhaps but on the latest Dell R730 config sheet I see:    Given the context of the R730 chassis, does anyone know what MLK signifies here?  I'm coming up with the obvious Media License Kit but that doesn't relate to a chassis...  Martin Luther King or Major League Kick ball...    Maybe it's Makin Life Crazy cause I am just drawing a blank here this morning.
What does MLK mean?