[exim] Is this still supported?

Is net24-lsearch still supported? I'm using exim 4.60 at the moment. And
if net24-lsearch is supported what about net16-lsearch or even
net8-lsearch. I under stand that the net24-lsearch will search a
document for a 0.0.0.0/24 format, but I want to block Class B's and
Class A's. Is that possible?

Here's what I have in my exim.conf, which is mostly from the original
guy who set it up be during the exim 3 days. Is this right or is there a
better way to do what I'm looking for?

drop    message = Your mail system is listed at $dnslist_domain.  Good-bye.
           dnslists = dnsbl.njabl.org:bl.spamcop.net:sbl-xbl.spamhaus.org

   drop    message = Host is denied in recipient-controlled access 
list.  Contact recipient for details, they are responsible for blocking 
your messages.
           hosts =   partial-lsearch;/etc/exim/blocked-hosts
           hosts =  +include_unknown:partial-lsearch;/etc/exim/blocked-hosts

   drop    message = Address is in recipient-controlled access list.  
Contact recipient for details, they are responsible for blocking your 
mail.      
           senders =  /etc/exim/blocked-senders

   drop    message = Host (24) is denied in recipient-controlled access 
list.  Contact recipient for details, they are responsible for blocking 
your messages.
           hosts =   net24-lsearch;/etc/exim/blocked-hosts : 
net-lsearch;/etc/exim/blocked-hosts
           hosts =  +include_unknown:net24-lsearch;/etc/exim/blocked-hosts