Make an entry in the first box. The other boxes are optional. You will get more hits with the Profiles box not checked. Find members by keyword. Or find by full or partial name.
Web Rings are collections of associated web pages with the same or similar interests.
These may be social, political or other interests. Your kind of bad guy may be using one of these. Abbreviations for any of the above. Other USPS info and contacts. It's probably rented from Mail Boxes Etc.