ZWR

Z-code: You are weak-readable

ZWEI

ZWEI Was EINE Initially (recursive acronym; see EINE)

ZWEI

Zwei Was Eine Initially

ZUT

(2)Zeta Upsilon Tau, 60s US Coast Guard radio op society

ZUT

(1)Unofficial Z-code: ""CW Forever!"" (see CW)

ZUH

Z-code: Unable to comply

ZUC

Z-code: Unable to comply until ----

ZT

Zone Time

ZST

Zone Standard Time

ZSR

Z-code: You are strong-readable

ZRO

Z-code: How copy?

ZRF

Zero Retention Force

ZPRSN

Zurich Provisional Relative Sunspot Number

ZPG

Zero Population Growth

ZNY

Military Z-code: Do not forward this message unencrypted by

ZNY TTTTT

Security Warning Signal: Message is TOP SECRET