A comparison file is automatically created in the Change Summary section when a document is being reviewed. The file is a PDF file showing the differences between the two files and includes a DO NOT DISTRIBUTE watermark.
Currently, the change summary will only be generated when the file associated with a document is an MS Word file. Other file types do not generate a summary file. (In the event that a summary file of changes cannot be automatically generated for any other reason, a notice will be displayed to inform the user.)
It's also worth noting that while the change summary can be generated automatically, it's also possible to manually attach any other file type as a change summary on a document. Thus, if, for example, the file type is not an MS Word file, or if the summary of changes could not be generated, a file listing the latest changes could be attached instead.
The attached document and the video below provide information on this feature.