RewriteEngine    on
RewriteCond    %{HTTP_REFERER} !^$
RewriteCond    %{HTTP_REFERER} !^http://([-a-z0-9]+\.)?xyz\.com [NC]   ## allow
RewriteCond    %{HTTP_REFERER} !^http://([-a-z0-9]+\.)?pqr\.com [NC]     ## allow
RewriteCond    %{HTTP_REFERER} !^http://([-a-z0-9]+\.)?abc\.org [NC]      ## allow
RewriteRule    \.(gif|jpe?g|png|gif|bmp|jpe|mov|mpg|avi|mpeg|jpg)$ http://www.mnr.com [NC,L]   ## Forward