I have the following questions regarding Attachments in Quality Center. We are currently upgrading from QC 10 to ALM 11.52. We have a loophole in our environments where users are able to attach a file to Quality Center and get it into our Clone(testing) environment.

1) Can we see who attached the file?
2) Once it is attached, is it always there or can it be deleted? If so, is this tracked? Is there history available?
3) Can the attachments be limited to a particular type of file? (I see there is a configuration parameter to limit the size of a file, but what about the type?)