Hi Edward, you're right. The beta website link is https://beta.boost.org/ FYI, there is a file 'libraries.txt' in the source codes which contains all the libraries info. It looks like that it can be generated by a site tool. To my codes review, there exist multiple records for a library for various versions in the above text file. And the codes check and compare a library record’s version info with the current version, and pick one matching a condition. There is no record with 'cxxstd' field at the text file for beta website but for main site. Unfortunately, there is no one to match version comparison condition for main site as well at the moment. The updates codes of beta website will only show 'C++ standard minimum level' with 'cxxstd' value only if a 'cxxstd' value exists.