Stephane Bortzmeyer wrote: > On Thu, Nov 30, 2017 at 01:36:00PM +0100, > Martin Hoffmann <mar...@opennetlabs.com> wrote > a message of 297 lines which said: > > > GLOBAL DNS -- FORMAT OF NAMES > > > > | Names in the common display format are normally written such that > > the | directionality of the writing system presents labels by > > decreasing | distance from the root (so, in both English and C the > > first label in the | ordered list is right-most; but in Arabic it > > may be left-most, depending | on local conventions). > > > > The first sentence makes it sound as if right-to-left languages > > would normally write ‘com.example’ which is not the case. > > BiDI is complicated enough so I suggest we keep only examples where > the script of the domain name is the same as the parent script. This > way, sentences like "The TLD is at the end" are always true. Writing a > latin domain name in arabic is left as an exercice for the reader :-)
RFC 5893 cleverly declares a "network order" and for it only speaks in terms such as "previous" and "next" with regards to the order of octets on the wire. This avoids the need for using left and right entirely even though it is clear to a reader that "example" is previous to "com" when written as "example.com". That said, there seems to be a mistake in the text for the common display format: | so, in both English and C the first label in the ordered list is | right-most Previously this list was defined as being "ordered ordered by decreasing distance from the root" which would make the first labal in this list to be the left-most label in English. > > under these circumstances the name will always be in the ‘usual’ > > order. > > I challenge this assumption. After all, numbers in arabic are > sometimes big-endian and sometimes little-endian (depending on wether > you are in the Middle-East or in North Africa). I wouldn’t dare claim to understand the Unicode Bidi Algorithm, but it seems to me that with the somewhat academic exception of names not containing any ASCII letters and ignoring any shenanigans with explicit overrides, domain names in common display format (that is, before any possible IDNA processing) would always end up as a single left-to-right run. Kind regards, Martin _______________________________________________ DNSOP mailing list DNSOP@ietf.org https://www.ietf.org/mailman/listinfo/dnsop
