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 60,744,344 websites Really Simple Discovery Customers. We know of 30,167,880 live websites using Really Simple Discovery and an additional 30,576,464 sites that used Really Simple Discovery historically and 3,312,275 websites in the United States.
Get a list of 60,744,344 websites using Really Simple Discovery which includes location information, hosting data, contact details, 30,167,880 currently live websites and an additional 2,200,805 domains that redirect to sites in this list. 30,576,464 sites that used this technology previouslyand 3,312,275 websites in the United States currently using Really Simple Discovery.
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