The acronyms generally are easy to decipher, but every manufacturer just makes up their own scheme.
BH is generally bunkhouse
RL is usually rear living
DS is double slide, deep slide, or Dinette slide
FK is front Kitchen
RB can be rear bath, or rear bed
S at the end usually means it has at least 1 slide
RE is generally rear entertainment
My camper is a 260TRS. Which means Terrain Rear Slide. Outback Terrain names all their models TRS though, even if they don't have rear slides, so it can be misleading.
Also the numbers at the front are often meaningless. Mine, the 260TRS is 29ft toal, my brothers is a 26RES and is 33ft long.