<hr /><i>anonymous added on 2010-09-27 08:51:10:</i><br />
Attachments and checkouts both result in files transferred from the repository to the user, but it is not clear that the same permission flag (checkout) should be used for both.

The wiki/ticket system attachments are informational in nature and could be of interest to users who are not developers, to whom checkout is usually restricted.

I suggest that ability to read a wiki/ticket should be sufficient privilege to download any attachment to it.