As we all know, xenForo automatically adds a rel=nofollow tag for external links with no exception.
Many of boards owners have multiple websites and would like their other "friendly websites" to be followed by search engines. Others may want to disable the "nofollow" tag for specific URLs for other reasons.
The solution is a "nofollow whitelist", xenForo wont add "nofollow" tag to the URLs in the list.
Also, It would be very useful to control the "nofollow" tags over specific posts or threads.
Like this post if you support the idea.