In message <[email protected]>, Jim Reid writes: > On 29 May 2014, at 18:56, [email protected] wrote: > > > Out of curiosity, where did the prohibition of underscores in host names > > come from. I'm sure there's a historical reason for it, but I've never > > heard it. Or is it really as simple as "RFC 952 only listed thirty seven > > characters" > > I believe this was a limitation of the (pre?) NCP-era ARPANET and may well ha > ve been a side-effect of the capabilities of operating systems from that era. > See RFCs 226 and 229.
One needs to decide what forms a name and what doesn't. Is $ part of a name. Is @ part of a name. Etc. Letters, digits and hyphen let you express labels with joined words. In English if you are joining words you use a hyphen. It was logical to join words using a hyphen to form labels from that. Additionally when you underscore a name you loose the distinction of whether a underscore is part of a name or not. Many current users have never used equipment where this distinction is lost. With modern displays you can have a underscore with a underline. For some reason someone decided to use underscore rather than hyphen to join words when making a labels despite hyphen being there to perform that role. This took off in the DOS/Windows world. What didn't help was software that didn't sanity check names. Mark > _______________________________________________ > dns-operations mailing list > [email protected] > https://lists.dns-oarc.net/mailman/listinfo/dns-operations > dns-jobs mailing list > https://lists.dns-oarc.net/mailman/listinfo/dns-jobs -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: [email protected] _______________________________________________ dns-operations mailing list [email protected] https://lists.dns-oarc.net/mailman/listinfo/dns-operations dns-jobs mailing list https://lists.dns-oarc.net/mailman/listinfo/dns-jobs
