DH = Dear Husband or Darling Husband
DD = Darling Daughter
DS = Darling son
DGS = Darling grandson
DGD - Darling grand daughter
DDIL = Darling daughter in law
and so on...
Some others are 'shortcuts' for phrases used when texting. Like "LOL" = laugh out loud
ROFLAO - Rolling on the floor laughing my *ss off
I'm still figuring them out because I'm don't do much texting.