For one long document, you can create AutoText entries or

text expander entries that include blank input fields. Blank fields are inserted with Ctrl + F9. You would insert the entry, then "jump" to each field by pressing the F11 key to input your variables. Whether or not you create one entry or six would depend on the way you work.

Look up Fields in Word's Help file for more information on the use of other fields (such as automatic dates). Also look up AutoText and AutoCorrect in the Help file.