XMT
From InterceptRadio.com Wiki
In Washington state, vehicles that are exempt from licensing fees do not display license tabs and have the "XMT" designation printed vertically where the first character would be. The last letter indicates registered owner:
| B | State agency |
|---|---|
| C | County agency |
| D | City |
| E | State agency |
| K | State DOT |
| M | State motor pool |
State Patrol vehicles are the exception; all non-ADAT vehicles are licensed "WSP xxx".
