3.1.1.2.2.4.13 UnicodeString Comparison Rule

Comparison of values using this comparison rule is performed via Unicode comparison, which is specified in section 6.5. If an LDAP_SERVER_SORT_OID extended control (see section 3.1.1.3.4) is attached to the search request and specifies a locale in its orderingRule field, the locale specified is used for the Unicode comparison. Otherwise, the Unicode comparison is performed using United States English (LCID 0409). The comparison function is independent of the server locale and therefore gives the same result on all DCs. The comparison function operates on Unicode strings containing characters from all alphabets and does not, for instance, involve reducing the string to the alphabet used by United States English before performing the comparison. This comparison function is used to determine both equality and ordering (greater-than-or-equals and less-than-or-equals), as well as to determine equality of substrings when performing a substring comparison.

This comparison rule is used in processing search filters, not in sorting search results. See section 3.1.1.3.4.1.13 for per-locale sorting of search results.