3GR-Three Girls Rattery, WA
6H-Sixth Happiness, IL
ALR - Amber Light Rattery, WA

AR-Aristorats, IL

BB-Brooklyn's Best 

BH-Birch Hill
BN - Bellaratta's Nest, FL

BR-Blue Ridge

CCR-Cathi's Critters Rattery

CVF-Colony at Valley Forge
CWR - Curly Whiskers Rattery
DC - Daisy Chain Rattery, WA (not breeding)
DCR - Deer Creek Rattery

DM-Donamays Rattery

DrD-Dr. Dolittle's

FP - Fur People, CA

JR-Just Rats

KF-Kissy Face Rattery
KTZ - Khat's Rats, OR
KR - Kabrin Rattery, WA (not breeding)

LL - Lizzie's Lovelies, CA
LM-Laurie Miner

LR-Little Ratscals
LSRC - Lone Star Rats of Central Texas

MAR-Marwin Ratties, MO

MC-Mary Crittenden

MN-Mixed Nuts

MNM-Mischief N' Mayhem (not breeding)

MRC-Minnesota Rat Connection, MN (not breeding)

MSR - Moonsong Rattery, WA (not breeding)

MY-Myomorpha, IL (now 6H)

NWSSR-Northwest Silver Star Rodentry, WA (not breeding rats)
OFR - Oddfellows Rattery, WA
OP - Opaline
PBR - Phi Beta Rattery, CA
PK - PK Rattery, FL

PS-Pat Sutcliffe
RF - Ratty Friends Rattery, WA (not breeding)
RH - Raffin House

RHR-Raven's Heart Rattery

RMR - Rodentia Madre Rattery, WA (not breeding)

RnR-Rat n Rave, MI

Rogue's-Rogue's Rattery

RR-Richland Rats

RRR-Rattie Room Rattery, IO (not breeding)

RSCL-Rattie Rascals Rattery, WA (us)
RvR - River Rats
SPR - Spiralrat Rattery, WA

SRR-Spoiled Ratten Rattery, MO

STAR-Star Rattery (not breeding)
WWR - Whispering Wise Rattery, CA

YOTR-Year of the Rat

For other breeder & rattery initials see the Ratster