last [<channel>] [--{from,with,without,near,proto} <value>] [--nolimit]
Gives the last URL matching the given criteria. --from is from whom the URL came; --proto is the protocol the URL used; --with is something inside the URL; --without is something that should not be in the URL; --near is something in the same message as the URL. If --nolimit is given, returns all the URLs that are found to just the URL. <channel> is only necessary if the message isn't sent in the channel itself.
This config variable defaults to "", is network-specific, and is channel-specific.
Determines what URLs are not to be snarfed and stored in the database for the channel; URLs matching the given regexp will not be snarfed. Give the empty string if you have no URLs that you'd like to exclude from being snarfed.