Possible replies one could imagine, encoded as SGML:
a normal HTML document
Document with preprocessing instructions:
<header>normal HTML</header>
<body class="break-word">asdfghjklsdfghjklasdfghjksdfhjkzxcvbnmeryuioxcvbjewft76t8yytcvncncnryxmry02zmxnxjxb7wdtx7b7rtwbt87</body>
A response indicating that authorisation is required:
This is a Delphi collaboration document. You can only access it if you can identify yourself as a Delphi member.
An error response:
Sorry, you can only access this object within the CERN site for copyright reasons. Complaints to Mr Bloggs.
A forward response with a set of possible forward addresses:
<link type="forward" href="http://junk.edu/junk/junk.ps">
<link type="forward" href="http://fred.com/junk/junk.ps">
Directory lookup successful.