This may seem trivial, but making something "related" to something else is like appointing a Supreme Court justice or a Pope -- you're stuck with that decision until one of the related items dies.

I made this mistake while playing with a note and I had to resort to creating a new note, copying the contents from the old note and then delete the old note to get rid of the connection -- yikes!

I'm lucky that the item which I would up assasinating in order to get rid of the rel didn't have other useful content (e.g. attachments, other relationships, tags etc.)