[Haskell-beginners] Need help with HXT

Greetings. I am trying to move some very old code from using HaXml to HXT. This is experimental; I have reasons which I think are not relevant to this post. The website that purports to document HXT has broken links. This is Uwe Schmidt's website. I have emailed Dr. Schmidt. Meanwhile, can anyone elucidate the use of readDocument with its withCurl and withHTTP options? What may be passed in the list to e.g. withHTTP? - Phil -