From Opus

[edit] What are Attachments?

The attachment feature of this forum gives you the ability to attach files of certain types to your posts. This could be an image, a text document, a zip file etc. There will be a limit to the file size of any attachments you make.

[edit] Attaching Files

To attach a file to a new post, simply click the [Manage Attachments] button at the bottom of the post composition page, and locate the file that you want to attach from your local hard drive.

After posting, the image attachments may display a thumbnail, depending on the forum settings. To view the contents of the attachment (if it is not already displayed) simply click the filename link that appears next to the attachment icon.

[edit] Managing Attachments

To view and manage the attachments that you have, view the attachments section of your control panel.