>>>>> "Jacques" == Jacques <jdh at ananzi.co.za> writes: Jacques> Why is it illegal to use underscolls Jacques> (_) like 123_345.yy.com bind spits out Because RFC1123 and RFC952 say so. Hostnames can't have underscores in them. Domain names can. A legal host name can only be built from the characters [a-zA-Z0-9-]. And "." obviously.