Preventing Editing or Formatting Changes
Sometimes you will want people to be able to open and view a document but not make changes to it. Sometimes you will want to allow changes, but only if you know about them. You can specify that only comments can be inserted in the document, or you can require that changes must be made using change tracking. To prevent anyone from introducing inconsistent formatting into a document, you can specify a selection of styles that must be used.
Control revision and comment balloons separately
To protect a document ...