Hi,

I'm trying to figure out the configuration options available for approximate/phonetic/accent-insensitive search on OpenLDAP (2.4).

First off, is there any documentation that I might have missed? I only found mention of an approx index without further details... nothing about what needs to be enabled etc.

In some older questions (~2002) an option "--enable-phonetic" was mentioned... was this removed respectively is it obsolete (e.g. the default)?

I did some tests using the approximate match operator ~= once on a fresh LDAP with no approx index and once with the approx index set and I got the same result... is this expected behaviour that approximate matching also works without defining an index? If it's not necessary, what's the advantage of setting the approx index, improved performance? (Mind that the attributes I search do have other indices set e.g. sub. Maybe approximate search implementation also considers that index?)

Since data in our LDAP is mostly French, Italian and German I was wondering if any language specific settings can be made? I came across a related question from 2015 which then was answered with no, is that still true?
> Is there any possibility to configure phontic search specially for Austria?

ITS is for bug reports/enhancements.  Use the openldap-technical
mailinglist for help reqests.

Anyway: No, soundex/metaphone is hardcoded in slapd approx match.
See <openldap source>/servers/slapd/phonetic.c.  Clients can do
a little of this "by hand" by inserting many variants of a name
(e.g. o instead of รถ) as invisible attribute values in the
directory, see the x-hidden examples in man slapd.conf.
http://www.openldap.org/lists/openldap-bugs/201506/msg00002.html

Could matching rules be used in any way to influence the search behaviour with regard to localization e.g. using collation? I came across "caseIgnoreOrderingMatch" (RFC 4517) but as far as I can see it's only good for sorting...
Is there a way to search only ignoring the order or in other words performing an accent-insensitive search?

Any other hints/best practices for configuring OpenLDAP to support approximate/phonetic/accent-insensitive search in general and specifically for languages other than English?

Thanks for your consideration.
Clauds