The Document Property is a Quick Parts feature in Microsoft Word to add Building Blocks which are text used often saved in a Gallery.

In Microsoft Word, you can insert built-in or custom fields into your Word document that may change within your document. Learn how to insert a Text field in Word.

In the article How to add an automated signature to a Microsoft Word document, I showed you how to use Quick Parts in Word to insert a graphic of your signature.

How to Automatically Insert the Document Filename in Word. Headers and footers in Microsoft Word often display the document's filename, and the name may appear at various points throughout a document.