...<br><div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><div>
<br>
</div>Right. We chartered work to make changes to IDNA2003. You seem to be<br>
arguing that we should not have done that. As I already remarked,<br>
that's a big claim and I think you will need to defend it.<br></blockquote><div><br>I think all of these issues are a matter of balance. Standard engineering practice, at least where I sit, is "don't break compatibility unless there is high benefit and low impact". The contention we are faced with is where people's assessments of the relative benefits and impacts are much different. <br>
<br>There are three compatibility breaches in IDNA2008:<br><br>a. mapping<br>b. symbols<br>c. deviations (eszed, final-sigma, joiners)<br><br>I think that from the point of view of users, browser vendors, emailer vendors, and search engines, that it breaks down as follows, for lookup:<br>
<br><b>Mapping. </b>The benefits to removing mapping are negative, and the impacts (compatibility) are also high. Luckily, however, mapping and the choice of it are optional. So even if IDNA2008 doesn't supply a compatible mapping, it can be supplied by Unicode, and I think all the important implementations would hew to it. (This is one area where lookup and registration differ - I think we're all agreed that as to the benefits/impact for the registration side).<br>
<br><b>Symbols. </b>The
benefits to removing symbols are negligible (the purported benefits were never backed up by evidence), but the impacts
(compatibility) are very low. So this is where important implementations could hew to the IDNA2008 (if there are no other issues).<br><br><b>Deviations. </b>This is the crux. Users want these characters, so the benefit is medium-to-high. But from the viewpoint of a search engine and browser vendors, the impacts are quite high; and it appears that from AT and DE NICs viewpoint as well, unless we can come up with an effective transition strategy (that may, however, be possible - see other messages).<br>
<br>Mark<br></div></div>