at "webmasters.stackexchange.com" I already found a similar topic: Stop directory listing using .htaccess and redirect to good error page
Options -Indexes
ErrorDocument 403 /path/to/403.html
However, now I want to distinguish between whether there was actaully a directory listing request issued OR if the user tried to access a protected area (through htaccess) unsuccessfully.
Both fire a 403, now how do I know which was the reason (the directory listing or the htaccess AuthName... thing) ?