You can use the little red exclamation point to make notes that you should see the next year when you go back to look at the previous year.  If that doesn't work for you, attach a note to the client's last name and that will carry from year to year until you no longer need it.  Be certain to put the date on the note the first time you do that.  Information from 2016 isn't always helpful on 2021 returns.  These are rather elementary suggestions but sometimes there is no other choice.

Another Former All Star