* comment: LDAP attribute for preferred language.
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getLdapAttrPreferredLanguage();

    /**
     * Get the value for the key 'ldap.attr.departmentNumber'. <br>
     * The value is, e.g. departmentNumber <br>
     * comment: LDAP attribute for department number.