Subject: Re: Active Directory question

From: Hallvard B Furuseth <[email-masked]>
Date: Fri, 7 May 2004 19:42:34 +0200

Kurt D. Zeilenga writes:
> At 10:27 AM 4/20/2004, Kurt D. Zeilenga wrote:
>>At 09:49 AM 4/20/2004, Hallvard B Furuseth wrote:
>>>Jim Sermersheim writes:
>>>>> _Can_ we recommend against unsolicited options? An attribute type with
>>>>> an option is a subtype of that attribute type without the option. A
>>>>> search requesting an attribute also requests subtypes. 
>>>>  
>>>> That's only true of tagging options (so far)
>>>
>>>Oh, good.  Seems to have been fixed since rfc2251 section 4.1.5:
>>>
>>>   An AttributeDescription with one or more options is treated as a
>>>   subtype of the attribute type without any options.
>>>
>>>This should be listed in [Models] Appendix A.1: Changes to RFC 2251.
> 
> I really don't see [Models] as changing the substance
> of what RFC 2251 said in regards to options and subtypes.
> [Models] just clarifies the sentence you quote as
> applying generally, but in all cases.

I don't understand.  The RFC 2251 statement seems general enough, while
[Models] clearly says it is _not_ general, and _not_ applies to all
cases.

> RFC 2251 included
> the same substance, it just wasn't as clear (because
> some folks sometimes took "is treated as" as "is").

I'm not sure what the practical difference is between "is" and "is
treated as", but in any case, RFC 2251 makes no distinction between
tagging options and other options with regards to subtyping, while
[Models] does.  I don't see how that can be no change.

-- 
Hallvard

---

From: "Kurt D. Zeilenga" <[email-masked]>
Date: Fri, 07 May 2004 11:18:06 -0700

>> applying generally, but in all cases.

I likely meant "but not in all cases".

>[Models] clearly says it is _not_ general, and _not_ applies to all

"treat as" doesn't necessarily mean "is a".

[Models] and [RFC 2251] are pretty close here.  Both
indicate that some options indicate descriptions which
are subtypes and some don't.

>tagging options and other options with regards to subtyping

But it does.  Consider the text regarding the ;binary option
in [RFC2251,2252,2256], cn;binary and userCertificate;binary are
clearly NOT a subtypes of cn and userCertificate respectively.

>, while [Models] does.  I don't see how that can be no change.

Because, I think, your taking one sentence out of context.

Kurt

---

From: Hallvard B Furuseth <[email-masked]>
Date: Fri, 7 May 2004 20:42:29 +0200

Kurt D. Zeilenga writes:
>>>>>>> An attribute type with

Well, like I said, I'm not sure what the practical difference is.

> are subtypes and some don't.

I still don't see the RFC 2251 text which says so.

You are right that ;binary seems to be a counterexample, but that just
means RFC 2251 is inconsistent, not that the existence of ;binary
overrides the description of other options.  Nor does it say that it is
;binary being a non-tagging option which is the reason it is different.

If you refer to something else with me taking the RFC 2251 sentence out
of context, I don't see it.

(BTW, I think I could make a case for foo;binary being a subtype of foo
but with various additional semantics, but I'm not sure if I want to go
there:-)

-- 
Hallvard

---

From: "Kurt D. Zeilenga" <[email-masked]>
Date: Fri, 07 May 2004 12:49:04 -0700

I've added:

Clarifications to these portions include:

- Attribute descriptions with options, while generally treated as    
subtypes of the attribute type, do not necessarily refer to
actual subtypes of the attribute type.

to A.1.2.

Kurt

---

From: Hallvard B Furuseth <[email-masked]>
Date: Wed, 19 May 2004 13:06:03 +0200

> actual subtypes of the attribute type.

Sorry to be going on about this, but I still don't get it.  That is not
what [Models] says.

- I can find no text in [Models] which implies that attribute
  descriptions with options are 'generally treated as subtypes' of the
  attribute type.  Only tagging options are defined to do so.  For other
  options to produce subtypes, these options' specifications would have
  to say so.  So I maintain that this is a change, not a clarification.
 
- Attribute descriptions with tagging options _are_ (description)
  subtypes (section 2.5.2.1), not merely _treated as_ subtypes, whatever
  the practical difference is.  Unless the "(description)" part reflects
  "treated as", somehow.

-- 
Hallvard

---

From: "Kurt D. Zeilenga" <[email-masked]>
Date: Wed, 19 May 2004 07:10:17 -0700

>Sorry to be going on about this, but I still don't get it.  That is not

Okay, I'll change the bullet to:

- Subtyping and AttributeDescriptions with options.

Kurt