What I’ve seen work on other forums is to have a designated “forum” (like chat or blogs, etc.) where newbies could post an introduction thread and specific people are semi-appointed to greet them. Of course anyone other FReeper is also free to offer their welcomes to the newby, not just the semi-appointees. Needless to say, it wouldn’t be a requirement for the newby to have to post an introductory thread but could if they wanted to.