We also support the Open Archives Initiative (OAI) protocol for metadata harvesting, a popular protocol in the library world. If your sitemaps are already available in OAI-PMH version 2.0 format, you are welcome to submit these. We also accept RSS 2.0 and Atom 0.3 syndication feeds, using the link/lastMod fields. FAQ を読んでいたらこんなことが書いてありました。RSS 2.0 もしくは Atom も Google Sitemaps へのリンクの通知に使えるのですね。なんで 1.
