This useful tool allows us to create neighborhood lists and bring them into our FedWiki neighbohood with the click of a button, or chevron as the case happens to be.
This plugin provides a hoverable, clickable roster of sites participating in a group activity. github 
Sites show as their flags. Click to open the site's welcome page. Hover to read its domain name.
Add multiple sites to the neighborhood by clicking the ยป that follow each row.
Write site domain names, one per line, to add them to the roster and show their flags on the page.
ward.wiki.example.com mike.wiki.example.com
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A lot of fancy stuff can be accomplished with rosters, as you might hope in a federation. Here are some instructions if you decide to get fancy.