STD Sexually Transmitted Disease
STD Screw the Dealer
STD Singly-Testable Dependent
STD Small Target Detection
STD Socially-Transmitted Disease
STD State Transition Diagram
STD Step Transaction Doctrine
STD Stick the Dealer
STD Stud Book
Z Zodiac
Z Zoloft
Z Zone
Z Zorro
Z Zuckung
Z Zulu Time
Z Zusammen
RUS Requisite Unifying Structure
RUS Resonant Ultrasound Spectroscopy
RUS Robotic Unmanned Sensors
RUS Rodents of Unusual Size
RUS Rural Utilities Service
Z is also for Zoran