RE: [xri-editors] RE: case sensitivity of XRI authorities

["Wachob, Gabe" <gwachob@visa.com>]

I just also thought of an issue of implementation. Does anybody actually *implement* these case folding functions yet? 

	-Gabe

> -----Original Message-----
> From: Dave McAlpin [mailto:dave.mcalpin@epokinc.com]
> Sent: Thursday, October 23, 2003 11:00 AM
> To: 'Wachob, Gabe'; 'Drummond Reed'; 'XRI Editors (E-mail)'
> Subject: RE: [xri-editors] RE: case sensitivity of XRI authorities
> 
> 
> Right, so there are really two questions.
> 
> 1) Do we want the XRI-authority component to be 
> case-insensitive, and if so
> 2) Is case-less matching as defined in Unicode 4.0 good enough?
> 
> The second is probably a question for Nat.
> 
> Dave
> 
> -----Original Message-----
> From: Wachob, Gabe [mailto:gwachob@visa.com] 
> Sent: Thursday, October 23, 2003 10:44 AM
> To: 'Dave McAlpin'; 'Drummond Reed'; 'XRI Editors (E-mail)'
> Subject: RE: [xri-editors] RE: case sensitivity of XRI authorities
> 
> +1 to Dave's proposal if the feeling is strong towards case 
> insensitivity in
> the authority part. 
> 
> Is there anything broken about applying that part of Unicode 4 to our
> current spec? 
> 
> 	-Gabe
> 
> > -----Original Message-----
> > From: Dave McAlpin [mailto:dave.mcalpin@epokinc.com]
> > Sent: Thursday, October 23, 2003 10:17 AM
> > To: 'Drummond Reed'; 'XRI Editors (E-mail)'
> > Subject: RE: [xri-editors] RE: case sensitivity of XRI authorities
> > 
> > 
> > That's a good summary of my proposal, although I think we'd 
> > probably cite
> > section 3.13 of the Unicode 4.0 spec rather than Unicode 
> > Standard Annex #21.
> > 
> > Dave
> > 
> > -----Original Message-----
> > From: Drummond Reed [mailto:drummond.reed@onename.com] 
> > Sent: Thursday, October 23, 2003 10:05 AM
> > To: XRI Editors (E-mail)
> > Subject: [xri-editors] RE: case sensitivity of XRI authorities
> > 
> > [Note: I moved this discussion to the Editor's list for archiving. I
> > also copied in Dave's second response re Unicode case rules 
> > so it would
> > all be in one place. =DSR]
> > 
> > Okay, so Dave's argument, as I understand it now, is that:
> > 
> > A) We should specify full Unicode 4.0 caseless matching for the XRI
> > authority segment because this should be true of ALL XRI authority
> > identifiers, this being the global portion of an XRI that 
> uses an XRI
> > authority.
> > 
> > b) We should not specify any case insensitivity rules for the 
> > rest of an
> > XRI path because that should be up to each authority.
> > 
> > To further summarize, this means that we are proposing that the 1.0
> > specification will say that there are only 3 places in which
> > case-insensitivity applies to ALL XRIs:
> > 
> > 1) Percent-encoding.
> > 
> > 2) URI authority segments using the rules specified in RFC 2396.
> > 
> > 3) XRI authority segments as specified in Unicode Standard Annex #21
> > (http://www.unicode.org/reports/tr21/tr21-5.html)
> > 
> > Does everyone agree with this proposal?
> > 
> > =Drummond 
> > 
> > 
> > ***DAVE'S ADDITIONAL RESPONSE***
> > 
> > Incidentally, the new Unicode 4.0 spec does describe caseless 
> > matching.
> > The
> > text was incorporated from
> > http://www.unicode.org/reports/tr21/tr21-5.html.
> > There are two or three corner cases that are problematic, 
> but the vast
> > majority of situations are covered.
> > 
> > 
> > -----Original Message-----
> > From: Dave McAlpin [mailto:dave.mcalpin@epokinc.com]
> > Sent: Thursday, October 23, 2003 8:16 AM
> > To: Drummond Reed; Wachob, Gabe; Lindelsee, Mike; Nat 
> > Sakimura (E-mail);
> > Peter C Davis (E-mail)
> > Subject: RE: case sensitivity of XRI authorities
> > 
> > Right, but that only addresses my problem if the global 
> namespaces are
> > case-insensitve, which puts us right back where we started.
> > 
> > Imagine DNS names were case sensitive. You visit a page 
> with a link to
> > http://www.Microsoft.com. You'd like to visit Microsoft's 
> > website so you
> > click the link. Unfortunately, www.Microsoft.com is a 
> > malicious site (as
> > was
> > the site that contained the link). You really wanted to go to
> > http://www.microsoft.com but were tricked into going to a rogue site
> > because
> > you, as a user, didn't know the proper case of the target site. That
> > would
> > be bad. It seems to me that case sensitive comparisons in the
> > XRI-authority
> > segment are bad for exactly the same reason.
> > 
> > With that said, I AM sensitive to the concern about 
> > internationalization
> > and
> > the message it sends to treat English language characters 
> differently.
> > Let
> > me ask the question this way - if there was a good 
> algorithm for doing
> > case
> > insensitive comparisons across the entire Unicode range, 
> > would you guys
> > support case-insensitivity in the XRI-authority?
> > 
> > Dave
> > 
> > > -----Original Message-----
> > > From: Drummond Reed [mailto:drummond.reed@onename.com]
> > > Sent: Wednesday, October 22, 2003 9:42 PM
> > > To: Dave McAlpin; Wachob, Gabe; Lindelsee, Mike; Nat Sakimura
> > (E-mail);
> > > Peter C Davis (E-mail)
> > > Subject: RE: case sensitivity of XRI authorities
> > >
> > >
> > > Dave,
> > >
> > > I find your argument compelling too. I agree that the authority
> > > component is a special case, that could be treated 
> differently that
> > the
> > > rest of the XRI.
> > >
> > > The biggest problem I have with saying XRI authorities should be
> > > case-insensitive is that XRI authorities, unlike URI authorities,
> > allow
> > > the full IRI character range (for which I think we all 
> > agree we cannot
> > > define case insensitive rules, unless we can adopt 
> > something specified
> > > by Unicode).
> > >
> > > If that's the case, then singling out the ASCII range for
> > > case-insensitivity in XRI authorities seems, well, a little
> > insensitive
> > > (pardon the pun ;-)
> > >
> > > An alternative is to say that BECAUSE XRI authorities are
> > > internationalized, case insensitivity is not specified at 
> > the level of
> > > the XRI spec, but can be adopted by any particular XRI authority.
> > >
> > > How do folks feel about that?
> > >
> > > =Drummond
> > >
> > > -----Original Message-----
> > > From: Dave McAlpin [mailto:dave.mcalpin@epokinc.com]
> > > Sent: Wednesday, October 22, 2003 6:08 PM
> > > To: Drummond Reed; 'Wachob, Gabe'; 'Lindelsee, Mike'
> > > Subject: RE: case sensitivity of XRI authorities
> > >
> > > You're right that this wasn't my original position. I'm 
> > willing to be
> > > outvoted, but consider the following.
> > >
> > > 1) The authority segment is special, primarily because we 
> define the
> > > resolution mechanics for it. I don't think it's 
> > inconsistent to define
> > > equivalence rules for it and be silent about 
> non-authority segments.
> > >
> > > 2) In fact, because we define resolution, I think we're obliged to
> > give
> > > guidance about case sensitivity in the authority component, 
> > one way or
> > > the
> > > other.
> > >
> > > 3) The authority component is the piece a user or 
> programmer is most
> > > likely
> > > to guess. That's certainly true for domain names and I'll bet it's
> > > equally
> > > true for xri authorities.
> > >
> > > 4) If the authority component is case insensitive, guessing is
> > > dangerous.
> > > For example, xri:@Nordstrom and xri:@nordstrom will resolve
> > differently
> > > (possibly to the same network endpoint, but they wouldn't be
> > equivalent
> > > by
> > > definition). That means that Nordstrom either needs to 
> register all
> > > possible
> > > case distinctions a user might reasonably guess or else be 
> > subject to
> > > spoofers. I think both options are bad.
> > >
> > > My preference is
> > >
> > > A) Percent-encoding is case INSENSITIVE.
> > > B) Both URI-authorities and XRI-authorities are case INSENSITIVE.
> > > C) Everything else is defined by the naming authority 
> that controls
> > the
> > > segment or subsegment in question (i.e. by its immediate parent).
> > >
> > > Dave
> > >
> > >
> > >
> > > -----Original Message-----
> > > From: Drummond Reed [mailto:drummond.reed@onename.com]
> > > Sent: Wednesday, October 22, 2003 12:58 PM
> > > To: Wachob, Gabe; Lindelsee, Mike; Dave McAlpin
> > > Subject: RE: case sensitivity of XRI authorities
> > >
> > > Ah, good, at least I think we're all on the same page now. Mike's
> > > argument about case sensitivity convinced me that C was the 
> > best path
> > > for XRI authorities, even though it's different than URI 
> > authorities.
> > My
> > > reasoning is that by not requiring in the spec for XRI 
> > authorities, we
> > > keep the option open for specific XRI authorities to 
> "narrow" their
> > > namespace to case sensitive, but that the spec itself 
> will be broad
> > > enough to allow for case-insensitive authorities.
> > >
> > > So, Dave, it seems that Gabe, Mike, and I would all prefer 
> > to adopt C.
> > > What's your stance?
> > >
> > > =Drummond
> > >
> > > -----Original Message-----
> > > From: Wachob, Gabe [mailto:gwachob@visa.com]
> > > Sent: Wednesday, October 22, 2003 12:33 PM
> > > To: Drummond Reed; Wachob, Gabe; Lindelsee, Mike; Dave McAlpin
> > > Subject: RE: case sensitivity of XRI authorities
> > >
> > > We are out of sync!
> > >
> > > C) is NOT agreed to. I like the position stated in C, but 
> I think it
> > the
> > > opposite of what we've agreed to.
> > >
> > > I gather that Mike L would follow whatever decision we made, so I
> > wonder
> > > what Dave's position is on case-sensitivity of 
> XRI-authorities. I'd
> > like
> > > to adopt the position in C)
> > >
> > >         -Gabe
> > >
> > > > -----Original Message-----
> > > > From: Drummond Reed [mailto:drummond.reed@onename.com]
> > > > Sent: Wednesday, October 22, 2003 12:29 PM
> > > > To: Wachob, Gabe; Lindelsee, Mike; Dave McAlpin
> > > > Subject: RE: case sensitivity of XRI authorities
> > > >
> > > >
> > > > First, my bad. My message said "So the conclusion is
> > case-sensitivity
> > > > only for percent-encoding and URI-authorities" and what I
> > > > meant was case
> > > > INsensitivity for these. Sorry, just not enough coffee this
> > > > morning ;-)
> > > >
> > > > Second, I'm still unclear from Gabe's message below. So 
> let me put
> > it
> > > > this way. I believe what we agreed on was that:
> > > >
> > > > A) Percent-encoding is case INSENSITIVE.
> > > >
> > > > B) URI-authorities are case INSENSITIVE.
> > > >
> > > > C) Everything else, including XRI-authorities, are case
> > > > SENSITIVE. (If a
> > > > particular XRI authority decides to apply case 
> INSENSITIVITY to a
> > > > namespace under their control, that's their perogative, 
> > but the spec
> > > > will not require that.)
> > > >
> > > > Does everyone agree?
> > > >
> > > > =Drummond
> > > >
> > > > -----Original Message-----
> > > > From: Wachob, Gabe [mailto:gwachob@visa.com]
> > > > Sent: Wednesday, October 22, 2003 12:03 PM
> > > > To: Drummond Reed; Lindelsee, Mike; Wachob, Gabe; Dave McAlpin
> > > > Subject: RE: case sensitivity of XRI authorities
> > > >
> > > > Wait guys!
> > > >
> > > > We're getting a little confused here.
> > > >
> > > > First of all, lets be clear about case-sentivity vs. 
> > INsensitivity.
> > > >
> > > > 1) I think we all agree that domain names (URI 
> > authorities) are case
> > > > INSENSITIVE and there is nothing broken about this.
> > > >
> > > > 2) The issue is about non-domain names (XRI authorities) - for
> > example
> > > > xri:+foo and xri:+Foo. Currently they are specified as case
> > > > INSENSITIVE
> > > > (meaning that US-ASCII characters as case-insensitive, 
> > but all other
> > > > characters, including, for example, Ñ and ñ are treated
> > > > differently - ie
> > > > case SENSITIVE). I'm not convinced this is required for URI
> > alignment
> > > > and in fact, I think its a bad idea given the Ñ/ñ situation I
> > > > mentioned
> > > > in a previous email.
> > > >
> > > > 3) And %-escaped characters are equivalent whether or not the
> > > > hex digits
> > > > are upper or lower case (ie %b0 is the same as %B0).
> > > >
> > > > Is this what everybody is agreeing to?
> > > >
> > > >         -Gabe
> > > >
> > > > > -----Original Message-----
> > > > > From: Drummond Reed [mailto:drummond.reed@onename.com]
> > > > > Sent: Wednesday, October 22, 2003 11:48 AM
> > > > > To: Lindelsee, Mike; Wachob, Gabe; Dave McAlpin
> > > > > Subject: RE: case sensitivity of XRI authorities
> > > > >
> > > > >
> > > > > Thanks, Mike. I recalled that your reasoning convinced me
> > > > and it still
> > > > > does. So the conclusion is case-sensitivity only for
> > > > percent-encoding
> > > > > and URI-authorities. XRI authorities can then of course
> > > > decide on the
> > > > > rules for their individual namespaces, but the spec will say
> > nothing
> > > > > about this.
> > > > >
> > > > > Done.
> > > > >
> > > > > =Drummond
> > > > >
> > > > > -----Original Message-----
> > > > > From: Lindelsee, Mike [mailto:mlindels@visa.com]
> > > > > Sent: Wednesday, October 22, 2003 10:30 AM
> > > > > To: Drummond Reed; Wachob, Gabe; Dave McAlpin; Lindelsee, Mike
> > > > > Subject: RE: case sensitivity of XRI authorities
> > > > >
> > > > > I was just reviewing that thread and Dave remembered the
> > > > > result of that
> > > > > discussion correctly.  We left it that percent encoding and
> > > > > URI-authorities would be case-insensitive.  I'm still not
> > > > > convinced that
> > > > > URI-authorities need always be case-insensitive (except in the
> > case
> > > > > where we are being backwards compatible with DNS names), but
> > > > > am happy to
> > > > > accept the wisdom of the group on this. ;)
> > > > >
> > > > > My reasoning, btw, was (imho) not particularly strong, but
> > > > still makes
> > > > > sense to me.  That is, unicode issues, 
> case-sensitivity in many
> > > > > filesystems, and case-sensitivity in account/resource naming
> > > > > all lead me
> > > > > to feel that it would be more flexible and forward-looking to
> > > > > not limit
> > > > > ourselves by declaring all of an XRI (or even just the
> > > > Authority part)
> > > > > case-insensitive.
> > > > >
> > > > > Mike
> > > > >
> > > > >
> > > > >
> > > > > > -----Original Message-----
> > > > > > From: Drummond Reed [mailto:drummond.reed@onename.com]
> > > > > > Sent: Tuesday, October 21, 2003 6:48 PM
> > > > > > To: Wachob, Gabe; Dave McAlpin; Lindelsee, Mike
> > > > > > Subject: RE: case sensitivity of XRI authorities
> > > > > >
> > > > > >
> > > > > > I know I'm late on this but I though Mike persuaded 
> > us all that
> > > > > > everything should be case sensitive. Mike, what was your
> > > > > argument, and
> > > > > > where did we end up after you made that argument?
> > > > > >
> > > > > > =Drummond
> > > > > >
> > > > > > -----Original Message-----
> > > > > > From: Wachob, Gabe [mailto:gwachob@visa.com]
> > > > > > Sent: Tuesday, October 21, 2003 1:04 PM
> > > > > > To: 'Dave McAlpin'; Wachob, Gabe; Drummond Reed; 
> > Lindelsee, Mike
> > > > > > Subject: RE: case sensitivity of XRI authorities
> > > > > >
> > > > > > I haven't changed the text as it is now, lets see if we get
> > > > > > comments on
> > > > > > it. I would guess their (URI) brokeness has to do with
> > > > the DNS case
> > > > > > insensitivity (they didn't think anyone else would 
> > come up with
> > a
> > > > > > different way of naming authorities i bet you).
> > > > > >
> > > > > >     -Gabe
> > > > > > -----Original Message-----
> > > > > > From: Dave McAlpin [mailto:dave.mcalpin@epokinc.com]
> > > > > > Sent: Tuesday, October 21, 2003 12:36 PM
> > > > > > To: 'Wachob, Gabe'; 'Drummond Reed (E-mail)'; 
> > 'Lindelsee, Mike'
> > > > > > Subject: RE: case sensitivity of XRI authorities
> > > > > > In the previous discussion, we decided to leave it broken
> > > > > with respect
> > > > > > to internationalization because Nat said it was impossible
> > > > > to come up
> > > > > > with a generic, case insensitive comparison 
> algorithm. At the
> > > > > > same time,
> > > > > > there was support for case insensitive comparison, so we
> > > > > > decided not to
> > > > > > throw the baby out with the bathwater and leave it enabled
> > > > > > for the ALPHA
> > > > > > production. Another way of looking at it is that we just
> > > > > > followed 2396's
> > > > > > lead on the authority portion.
> > > > > >
> > > > > > -----Original Message-----
> > > > > > From: Wachob, Gabe [mailto:gwachob@visa.com]
> > > > > > Sent: Tuesday, October 21, 2003 12:31 PM
> > > > > > To: Dave McAlpin (E-mail); Drummond Reed (E-mail); 
> Lindelsee,
> > Mike
> > > > > > Subject: case sensitivity of XRI authorities
> > > > > >
> > > > > > What was the resolution on this topic?
> > > > > >
> > > > > > We have the language in there about case 
> insensitive for alpha
> > > > > > characters.
> > > > > >
> > > > > > Is this what we concluded? I can't find a record in email.
> > > > > >
> > > > > > This is a little odd, of course, because for languages
> > > > like Spanish,
> > > > > > xri:+pequeño and xri:+Pequeño are the same but 
> > xri:+pequeño and
> > > > > > xri:+PEQUEÑO are different. That smacks of indifference to
> > > > > > internationalization concerns (its odd because 
> whether or not
> > the
> > > > > > upcasing/downcasing changes equivalence depends on which
> > > > > > characters you
> > > > > > use).
> > > > > >
> > > > > > My vote is against case insensitivity even in the
> > > > > "authority" part, at
> > > > > > least as a rule that applies to all xris. We could 
> > say that, for
> > > > > > example, within the + namespace, the naming 
> > authorities are case
> > > > > > insensitive (with whatever definition of case insensitivity
> > > > > we decide
> > > > > > makes sense), but it strikes me as broken to declare case
> > > > > > insensitivity
> > > > > > the way we have done it.
> > > > > >
> > > > > >     -Gabe
> > > > > >
> > > > > >
> > > > > >
> > > > >
> > > >
> > >
> > >
> > >
> > 
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