I figured this out. I noticed that several people had looked at this with no ideas coming back to me so I decided to dig deeper (again). Turns out that there is a "Layer 0" in our drawings that has the text mentioned above...
The layer does not show up in the CAD view or in a .pdf created from the drawing either, so I've never seen the text before. Also, Prime 1.3 and below (including WCS) strip this layer off automagically, but Prime 2.0 does not.
Fortunately on Prime's drawing import preview selected layers can be turned off. I started taking them out and when I turned off Layer 0 the text disappeared! Not sure why it doesn't show up in CADs or .pdf's, even though the layer is on. Thanks much to all who looked at this.