The 2 things I know of which come closest are: - P3P, which describes various ways a Web site intends to use your data, and browser preferences for what to al

The 2 things I know of which come closest are: - P3P, which describes various ways a Web site intends to use your data, and browser preferences for what to allow https://en.wikipedia.org/wiki/P3P https://en.wikipedia.org/wiki/P3P - Debian packages contain license information, and debconf can ask the user to read the license and accept/reject (in the case of non-Free software; Free Software can be used without agreeing to anything). The answers are kept in a database, so if a license has been agreed to it won't be asked again. This is similar to what you're asking, but assumes that there's a small set of possible terms, which projects/organisations reuse over and over.