A robots disallow all directive with no other options.
https://robotstxt.org
Robots.txt
Get access to data on 15,484,646 websites that are Robots Disallow Customers. We know of 5,581,000 live websites using Robots Disallow and an additional 9,903,646 sites that used Robots Disallow historically and 2,025,965 websites in the United States.
Get a list of 15,484,646 websites using Robots Disallow which includes location information, hosting data, contact details, 5,581,000 currently live websites and an additional 4,182,337 domains that redirect to sites in this list. 9,903,646 sites that used this technology previouslyand 2,025,965 websites in the United States currently using Robots Disallow.
Countries
Financial
Group
Region