If you go to a WWOOFer's or host's profile page, you will see a "comment" link at the bottom right of the page.
Click on it and add your comment. (see Flavien Mabit and Hannes Koch profiles)

I don't know HOW I missed it before. If it's always been there, I've obviously never 'clicked' on it. Shame on me - that's what I do, pick apart programmes and explore websites until I know exactly what they can and cannot do.

Noreen

p.s. - I was wrong, it's not ALWAYS there (thank goodness because I thought I was losing it ;P) - I just tried to leave feedback for another of our past WWOOFers (Chris Erlebach) and the "leave comment" link is not there. However, she does not have anything other than the basic info in her profile either - no personal comments about herself. So I am assuming if a WWOOFer does not add anything to their profile, nobody else can comment on them either. - Noreen

p.p.s. - OK, it's NOT that she didn't put any personal comments in, she did NOT fill in where she was from and where she is now. I just went to another of our WWOOFer's profiles (Arnaud Falisse) and he also has not put any personal comments in BUT he entered his home town, country and where he is now and the "comment" link was there.

p.p.p.s. - OMG, this is GREAT!!! You can even go back and edit it if you want to, and flag any comments you think might be "offensive".

p.p.p.p.s. - I just emailed John (admin) regarding my findings and he said it was a new feature implemented 2 days ago. The "flag" feature notifies ADMIN of inappropriate content.