[Verbosus]

Not naughty plate, but one I saw in a list reading Readers Digest years ago
that was cleaver was:
10SNE1 (Tennis Anyone)

There was another that only made sense when reading the mirror image from
your rear-view mirror (was not in the Reader’s Digest list):
3M TA3

I have an old plate hanging up in my garage that I got from a ZZ Top fan
(It was a real plate): ZZONCD (ZZ on CD)

And finally, for software/computer geeks that grew up with UNIX, here is
one from the late 70s and early 80s:
XYZZX (The ‘magic word’ from the old UNIX text game ‘Adventure’, which
would move you to another location within the endless cave with many
chambers.)

[DYngbld]

Its XYZZY. Ok so I am a dork. :)

[Slings and Arrows]

I remember that last one from ZORK. Good times...