Having auto-updating headers and footers helps you know which version of a document is which when it is printed. You can do this by inserting fields.
From the Field Names list select the field you want to insert and then press OK.
- FileName inserts the file name of the document including the extension.
- SaveDate inserts the date the document was last saved.
- NumWords inserts the number of words in the document.
Fields will automatically update when the document is saved. If you want to update them before that – say for example because you want to check the word count or you want to print out a version with the correct field information – you can do that through the right click menu.
Select the field or fields you want to update. Then right click and select Update Field from the dropdown menu
You can store these fields in a Word template so you don’t have to add them to documents each time.
If you want the fields to update on opening the document rather than saving them Duncan Drury has some nice instructions on how to do this using macros here http://dunxd.com/2012/08/08/word-2010-template-with-auto-updating-fields