"As New", "NOS", etc

I've seen quite a few ads using these terms, often quite loosely.

Just what the heck does "As New" mean? Something someone used and put back in the box and expects full retail price?

And "NOS"; shouldn't that mean an old, never sold, unopened item, and not something someone used a few times and put back in the box?

I can't find anything on the Audiogon listing guidelines about this.