I have two calculations set up for ABO, RH. One is called BT, and uses just ABD, AC BC ( with the last being cells). the other is the TYPEF calc and it has rules for WD and RHC, for controls. Which meditech version are you using? We just went to 6.0 Client server from Magic 5.62, and I had both set up. If you set up the TYPEF calc, use the label as DU for example but the trigger test is WD, then DUC and trigger being RHC for test. The target test for this is BT, which includes only ABO RH, and will report just A pos for example. Feel free to email me privately and I can send you some screen shots! lthedford@petersonrmc.com