List all open Documents
When dealing with a large number of documents, the built-in Visio method of selecting which document to view is far from ideal. Use the “List all open Documents” menu to select which document to view. It provides the document type and name to allow you to clearly see all the current documents that are open. The current document is highlighted. Note that if there are a very large number of documents then it can take a few seconds to populate the list.
To save the list of documents in a text file, use the 'Save' button.