[pmwiki-users] how to display download link only if file exists?

[SteP]

>... how to display a link only when an uploaded file exists and uploads
>are disabled? 

Never mind, I found the -I guess- canonical way to do it. Uploads should
be enabled with default password='*', then the format upload string for
non-existent files should be set to null, at which point Attach:file
works as expected to hide itself only when no file exists.