Board Thread:Support Requests - Getting Started/@comment-33672553-20180725030307/@comment-168424-20180725221647

A UUID is a new identifier like a MAC address, but for the PC (motherboard?) and not just the network adapter. Theoretically, browsers could pull the UUID from a machine and send it to a web site. However, support for UUID querying is not standardized as far as I know (I'm not sure any browsers actually do it), so it wouldn't be a reliable way to block unless getting it were part of the W3C standards.