https://publicsuffix.org/list/ https://publicsuffix.org/list/ (See the Algorithm) Is actually hard to implement correctly and interoperably, even among browser

https://publicsuffix.org/list/ https://publicsuffix.org/list/ (See the Algorithm) Is actually hard to implement correctly and interoperably, even among browsers, and there are sharp edge cases along the way (such as holes within domain trees). The author of the library referenced at least worked with the PSL maintainers and browsers to make sure they were faithfully and correctly implementing things :)