(Plug-in) Listings Spam Protection through no-follow Tag in Outgoing Links

[PGGO]

To avoid SPAM injection in listings, it will be nice to be able to add "no-follow" tag to all outgoing links from the listing details.

Most spammers know that no-follow tag does not pass any Page Rank juice, so they won’t post any spam listings.

In addition, it will be beneficial to add no-follow based on listing prior review.
For instance, some listing may be follow and some no-follow.