URLs were initially deisgned to be stable (and this is still a strong recommendation).
However I did not describe just URLs but URNs (whose URLs are just resolvers locating them). URNs share with URLs (and URIs in general, as well the UCS) the initial "U" which is intended to be universal (both in space but also in time). The problem being that it is still open to anyone that do not want to maintain this stability (but also because URLs have a limit of time which is the time of registration of their domain name, this limits their universility in time). The web also is currently having difficulties to maintain its universitlity in space (look for ongoing political discussions for its "neutrality"). URNs however should be stable... provided that there's a stable registry for maintaining the references. (the UCS is stable only because this registry exists and is managed by a joint authority which is also still managed and with enough participants so that no other attempts are made to concurrence it with the same success). Stability laregely depends on the status of the standard that supports it, and by the number of interested people that want to participate. It is never warrantied over a long time as any particopant may decide to retive from the project). But stability also requires that the participants do not change their mind in that project. Such such is less likely to occur if there are lot of users of the standard. Even the UCS has had its own history of instability in its early versions. And it's very difficult to maintain this stability when frequently there are people that contest this stability (sometimes in the UCS this means that a new proprerty must be designed to satisfy more people, but this also adds to the total cost of management of the whole standard, however new sets of characters are now slowing down. The remaining ones are a few isolates to complement existing scripts, or scripts that are extremely similar in structure to existing ones, for which compeltely new solutions rarely need to be designed. Most important difficulties are solved, even for the remaining scripts that need to be encoded ... except the more recent addition of emojis where we still cannot see how they will be bounded in scope (and I count flags within emojis), and scripts with complex layouts for which there are still missing standard solutions (e.g. SignWriting, hieroglyphs and old cuneiforms). We'll probably have more discussions about conventional symbols used in signalisation (e.g. signals on roads, including traffic lights, and marks on the ground), or conventional signs on products (standard conformance marks...) and various security related symbols. We know we are stable only for alphabetic/phonetic scripts, but we have lots of candidate symbols and ideograms (whose creation and explosion in definitely not terminated, and do not concern just CJK scripts). The industry and legislations are creating new symbols every day around the world... and also deprecating a lot at almost the same rate. So yes URLs can be stable, but only those from recognized standard bodies that want to maintain them stable (e.g. URLs to W3C standards are stable... but not necessarilyt all tose linking to temporary discussions. The same is true for URLs to temporary work documents used by the UTC or ISO, or W3C themselves where docuemtns may be moved elsewherein some archives and with other formats, loosing some formatting details). 2015-05-20 20:57 GMT+02:00 Doug Ewell <[email protected]>: > Philippe Verdy <verdy underscore p at wanadoo dot fr> wrote: > > > Well for now a reasonnably stable standard exists: URLs, that can > > point to a collection of pagenames (each site can choose its own > > registry to name/encode the flags) > > URLs are the opposite of stability. Anyone can post whatever they like, > publish the URL, then change or remove the content at any time.
