Re: Models: Matching Rule Uses

["Kurt D. Zeilenga" <Kurt@OpenLDAP.org>]

At 10:08 AM 2/13/2003, Hallvard B Furuseth wrote:
>Kurt D. Zeilenga writes:
>>At 01:17 AM 2/13/2003, Hallvard B Furuseth wrote:
>>> Well, the point is that if it may be a syntax which is not permitted by
>>> the restrictions I quoted from [Syntaxes], or whatever they are modified
>>> to say, that must be mentioned in [Models].
>> 
>> The data model places no restrictions on the specification
>> of matching rules in this area.
>> 
>> Can you offer a specific change to [Models] which attempts
>> to address your concern?
>
>If there are no restrictions,

The directory models place no restrictions on what kinds of
matching rules can be defined, but a matching rule certainly
is only (well-)defined for use with specific attribute value
syntaxes.  A server may publish any matching rule use it
knows as being defined.

>that would be:
>
>4.1.4:
>  "An attribute type can appear in a matching rule use even
>  if the corresponding matching rule definition in [Syntaxes]
>  does not allow the attribute type's syntax."

Just like rules listed in the attribute type description,
rules listed in matching rule use are listed when appropriate
per the technical specification of the attribute type, its
syntax, and the matching rule.

>I might note that this is _not_ how OpenLDAP works now.
>That creates e.g. a matchingRuleUse for caseIgnoreMatch
>which does not allow seeAlso, which has a different syntax.

Yes, because there is no specification is known by the server
which details the use of caseIgnoreMatch against attribute
values of distinguished name syntax.  But if such specification
were to come into existence and be known by the server, then
the server could publish it if it so chooses.

>Furthermore,
>  "If a matching rule has no corresponding matching rule use,"
>  ..."it can be used with any attribute type."?
>  ...or if not, when can it be used?

A matching rule can be used in an extensbleMatch search
filter any time the usage is well-defined.

Kurt