Question on padlock in potlatch

I was checking an area I had completed a while ago and noticed the roads were red instead of orange so I assumed the highway type was wrong but checking it was correct.
The road next to it was the correct color and I noticed the only difference was on the red road was a small padlock next to the way number. I clicked on the lock and it disappeared and the road is now correct.

Not sure where it came from and cannot find and mention of it in the potlatch doc.

Peter…

It looks like you pressed accidentialy “U” for undelete. This will bring up all deleted objects (in red) in the current view. If you click on the little padlock the object will undeleted.
Check: http://wiki.openstreetmap.org/index.php/Potlatch/Keyboard_shortcuts