Sign Under Test

As you may know by now, bad grammar and spelling bothers me.  I'm not perfect. But I strive to be.  And most of my work isn't in the public eye.

Every work day for the past couple weeks, I have driven past one of those digital highway signs, with a yellow and black sign affixed saying "Sign Under Test".

What does that even mean?  I know what they intend it to mean.  "Sign undergoing testing."  But that isn't what it says.

To me, it's a command to put my signature under the word "Test".  Or is it a command for ordering words in  reverse alphabetical order?  "Sign" goes under "Test".

Couldn't the sign have simply read "Sign Test:".  Short, succinct, and to the point.

Sigh.