If this is the same as the Yahoo sign-in password you may have been prompted to enter a key phrase when you first signed up (pet's name, first brand of car etc) as a way of retrieving your Yahoo password in case you forgot it.
It has been years since I original signed up for my Yahoo account; so, I do
not remember any of the information that I originally utilized when I set up
the account. I have had it setup for automatic login on a laptop for a long
time and want to utilize it on another laptop; but, I do not remember the
Yahoo Password Login. What do you suggest ???