Thanks ! Rachel’s post is a good starting point.
Update : perhaps this is not the right place to ask a question as the one I posted ? Should I address this in the hacker community of WP ??
Thanks for any suggestion you can give me.
Just one other thing : Pingback works ok (in/out), but incoming pingbacks appear between the comments. I would like to have them appear separately. And I do not want trackbacks… Pff, am I being too demanding 😉
