In some cases, a comparison may yield an undefined result, e.g. when the property being compared is not defined on both resources, or where it has incommensurable values. In such cases the server MAY use any order it likes. 7.7.1 Comparing natural language strings. For those properties that are natural language strings, the comparison may specify the natural language whose sort order is to be used. The comparison may also specify whether or not case is significant.
Most languages define sorting orders for strings expressed in their alphabet.
DASL provides means to request a single national sort order for a given comparison. A server that does not understand the requested language order requested MUST reject the request. A server MAY use any ordering it wishes for such comparisons. DASL does not define the sorting orders for any natural language.