Thanks for having the courage to ask. I've been on here 5 months and at first it was like "The what??" I also did not know MIL, DH, SIL, DD or any of those at all. Hope this makes you feel a little better.
MKM, I know what you mean. When I first came on board here I was wondering why so many seniors were moving to Alabama [AL], New Hampshire [NH] and Illinois [IL] not realizing those were abbreviations for Assisted Living, Nursing Home, and Illinois.... [sigh]
I really wish admin would make that information easier to find. And would be very helpful to those new to this site. It should be near the top on every page.
https://www.agingcare.com/articles/common-caregiving-abbreviations-and-acronyms-435589.htm