| KQC | key quality characteristics |
|---|---|
| KR | key-ridge; Kopper Reppart [medium] |
| Kr | krypton |
| kR | kiloroentgen |
| KRB | Krebs-Ringer buffer |
| KRBG | Krebs-Ringer bicarbonate buffer with glucose |
| KRBS | Krebs-Ringer bicarbonate solution |
| KRP | Kolmer test with Reiter protein [antigen]; Krebs-Ringer phosphate |
| KRR | knowledge representation and reasoning |
| KRRS | kinetic resonance Raman spectroscopy |