www

 www  in the context of the IndieWeb is an unnecessary subdomain on personal domain name. "www." used to be expected as a convention for websites on a domain, but has long since been abandoned.

See:
 * http://no-www.org/

On the other hand: the www subdomain can be useful when hosting a site on another provider's architecture (Withknown.com, Google App Engine, Heroku, Amazon S3, GitHub Pages or a CDN). To support a custom domain name and still provide load balancing, these services usually require a CNAME record pointing from your domain to a domain name they control. You cannot create a CNAME record for a naked domain, so www is a useful default.

See:
 * http://www.yes-www.org/