Keeping a record.
WHAT TO RECORD
Every plugin What it does Why it is there Whether it is paid, and when it renews Where the licence is held Any configuration worth remembering
WHY
In a year you will not remember why something is installed.
Someone taking over the site will have no idea.
WHAT THIS PREVENTS
Removing something important because nobody knew what it did Paying for licences on plugins no longer used Losing access to a licence held on someone else's account
WHERE TO KEEP IT
With your site documentation, off the server.
WHEN TO UPDATE IT
When you install or remove anything.
WHAT TO SCREENSHOT
Important configuration screens.
After an update resets something, that is how you restore it.
FOR A SITE YOU MANAGE FOR SOMEONE ELSE
This document is part of what you hand over.