When you are dealing with a document which can be used on both Mac and PC, it is always a good idea to find out where that document was originally created. For example the processing of a text document could be different since each platform has its own specific way of handling the linefeed. Determining the origin of the document can allow you to choose an appropriate action or procedure to handle the document's format. To do this, you only need to execute the command Document creator. That command returns the file creator if the document was created on Mac OS or an empty string if it was created on Windows.