Really Simple Discovery is a way to help client software find the services needed to read, edit, or "work with" weblogging software.
https://cyber.law.harvard.edu/blogs/gems/tech/rsd.html
Syndication Techniques
Get access to data on 58,595,802 websites that are Really Simple Discovery Customers. We know of 30,290,425 live websites using Really Simple Discovery and an additional 28,305,377 sites that used Really Simple Discovery historically and 3,403,226 websites in the United States.
Get a list of 58,595,802 websites using Really Simple Discovery which includes location information, hosting data, contact details, 30,290,425 currently live websites and an additional 1,871,223 domains that redirect to sites in this list. 28,305,377 sites that used this technology previously and 3,403,226 websites in the United States currently using Really Simple Discovery.
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