Powdered Milk (DMS)???

Making variation #1 hamburger buns from BBA, for tonight's dinner. Question for you guys/gals. ( Sorry, I try to be gender neutral, however, it's hard for me.)  What could DMS stand for in the powdered Milk ingredient? Ah, the fog has lifted. When I get in a depressed state a quick turnaround back to positive activity is always welcome. Smile... Thanks for any advice.

Kind regards,

Will Falzon