i havent looked at your javascript but i can guess how it works (or how to make a similar ring.) im planning to make one just for sites that have free-licensed stuff on them, like under free sw/free culture licenses, i thought you might find this interesting. youre doing a cool thing here.
its now implemented: https://freemedia.neocities.org/webring.html it checks the referrer for neocities websites, and if that doesnt work it allows someone to submit their site via ?site=address. it also requires just one link for each button, which means that it works from sites that noscript doesnt whitelist, provided that the site hosting the webring is whitelisted. you inspired this, with your use of only js.
its now implemented: https://freemedia.neocities.org/webring.html it checks the referrer for neocities websites, and if that doesnt work it allows someone to submit their site via ?site=address. it also requires just one link for each button, which means that it works from sites that noscript doesnt whitelist, provided that the site hosting the webring is whitelisted. you inspired this, with your use of only js.
Thank you! Tho I usually try to avoid JS. ;) I added my site, by the way.