joke :
"Your post has been changed because invalid HTML was found in the message body. The invalid HTML has been removed. Please review the message and submit the message when you are satisfied."
Tends to happen when you put a link in a message. Before it can be sent ebay remove any invalid HTML.
It may not change anything you are wanting to say, but ebay points it out to you to check that your message still says what you want to say, and that no parts have been removed/changed.
£0.00
Not as bad as the member threatened with debt collectors for unpaid fees of the same amount.