Some of you might have read the Feedback column in New Scientist, quoting Wendy Warr, who posts to this forum occasionally. The article is about the TheScientificWorldJOURNAL, and whether the case sensitivity matters or not. There is a comment that www.chemsoc.org must not be written www.Chemsoc.org etc etc. This issue has always lurked just beneath the surface, so I decided to see what the truth was. The reference is RFC 1034/5, the relevant part of which reads "The labels must follow the rules for ARPANET host names. They must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphen. There are also some restrictions on the length. Labels must be 63 characters or less." Letters are case insensitive for comparison but case preservation is recommended i.e. the server should reply with the same case the client sent." I think this means that it does not matter how you capitalise the FIRST PART of the web address (my capitals!), the DNS system should be able to resolve it to the correct web server. Whether eg ! is allowed seems very doubtful. But of course a URI as it is formally known comprises the DNS name and then a directory path and filename to complete the address. This WILL be case sensitive if the machine registered as owning the DNS name runs Unix, but is unlikely to be if its Windows or a Mac. How a prospective user is supposed to know what kind of machine hosts the web service is unclear. This aspect has often been described as one of the things the original Web design got most wrong. -- Henry Rzepa. +44 (0870) 132 3747 (eFax) +44 0778 6268 220 (Mobile) http://www.ch.ic.ac.uk/rzepa/ Dept. Chemistry, Imperial College, London, SW7 2AY, UK. chemweb: A list for Chemical Applications of the Internet. To post to list: mailto:chemweb@ic.ac.uk Archived as: http://www.lists.ic.ac.uk/hypermail/chemweb/ To (un)subscribe, mailto:majordomo@ic.ac.uk the following message; (un)subscribe chemweb List coordinator, Henry Rzepa (mailto:rzepa@ic.ac.uk)