I realize that on the surface, this is a dumb question -- just delete them all, and then when your websites don't work you will know that you made a mistake.
My question then: Is there a practical, systematic way to determine, other than by trial-and-error, which cookies need to be retained?
@Hey-Hey I've no idea what or why you are saying, but if you do post to the forum again make sure to make some semblance of communication and understanding possible with your posts.