Q-RPT stands for Quartz Reference Pressure Transducer
Q-PCR stands for Quantitative Competitive Polymerase Chain Reaction
Q-in-Q stands for 802.1q Tunnel Tags (Cisco)
Q-Day stands for Day for Dress Rehearsal of Atom Bomb Test (June 23, 1946)
Q-2-D stands for Quasi-Two-Dimensional (also seen as Q2D)
Q&Q stands for Quality and Quantity (marketing)
QBVD stands for Quantum Barrier Varactor Diode
QBTU stands for Quadrillion British Thermal Units
QBME stands for Quantum Boltzmann Master Equation
QABI stands for Quebec Association of Building Inspectors