The attachment section of the UCP shows a list of all attachments that you have uploaded to the board. Each entry contains a link to the message in which the attachment is contained, the size of the attachment, the number of times it has been downloaded, and the time at which it was uploaded. Through this page, you can delete attachments from the board. Inline references to a deleted attachment will still remain in the original post, but the attachment will not be rendered in any way other than the file name.