I've tried all I can. but I have found no way of saving / wblocking a file once I have made changes to it, using TrueView. I should add, that I have been using the 2009 version.
However, it is possible to create non-CAD file formats from the changes i.e. pdf / dwf etc and paper copies.
This in itself, is dangerous.
This kind of information will not be getting shared out amongst my office, as they are all mostly renegeade CAD'ders anyway; a little more information in their armoury would be dangerous imo