[1] Draft: PubSubHubbub Core 0.1 -- Working Draft ( 版) <http://pubsubhubbub.googlecode.com/svn/trunk/pubsubhubbub-core-0.1.html>
[2] RFC 5988 - Web Linking ( ( 版)) <http://tools.ietf.org/html/rfc5988#page-13>
[3] RssFeeds - pubsubhubbub - Support of RSS in PubSubHubbub - A simple, open, webhook based pubsub protocol & open source reference implementation. - Google Project Hosting ( 版) <https://code.google.com/p/pubsubhubbub/wiki/RssFeeds>
[4] Draft: PubSubHubbub Core 0.4 -- Working Draft ( 版) <https://pubsubhubbub.googlecode.com/git/pubsubhubbub-core-0.4.html>
The HTTP [RFC2616] response from the publisher MUST include at least one Link Header [RFC5988] with rel=hub (a hub link header)
<atom:link rel="hub" href="https://pubsubhubbub.appspot.com"/>
<atom:link rel="hub" href="https://pubsubhubbub.superfeedr.com"/>