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 57,319,375 websites Really Simple Discovery Customers. We know of 29,727,407 live websites using Really Simple Discovery and an additional 27,591,968 sites that used Really Simple Discovery historically and 3,453,505 websites in the United States.
Get a list of 57,319,375 websites using Really Simple Discovery which includes location information, hosting data, contact details, 29,727,407 currently live websites and an additional 1,784,455 domains that redirect to sites in this list. 27,591,968 sites that used this technology previouslyand 3,453,505 websites in the United States currently using Really Simple Discovery.
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