[Mimedefang] vcs extension

[Kenneth Porter]

I just got a legitimate text vCard attachment in my quarantine with a .vcs 
extension. It's in the list of bad file extensions in the default filter. 
Why is that? Is this extension used for some bad binary formats? Or can a 
vCard carry dangerous macros? I'm trying to decide whether to remove vcs 
from the list, since calendar files for appointments do seem like a 
legitimate thing to receive.

The sender was xtime, which seems to be an automotive dealer-customer 
management system, and it assigned application/octet-stream as the mime 
type of the attachment instead of a proper calendar type.

<https://filext.com/file-extension/VCS>