Yes, this is correct. While a preferred format for this particular sequence ID is defined in the ST.26 DTD, it is not generated by the tool. In fact, there is a verification rule that ensures that this element is not present in the XML. This field is intended for the use of IP Offices which exchange sequence listings with database providers only and not for data communicated between IP Offices. For further details see Annex V of WIPO Standard ST.26.
Format:
pat|{office code}|{publication number}|{document kind code}|{Sequence identification number}
where office code is the ST.3 two-letter code of the IP office publishing the patent document, publication number is the publication number of the application or patent, document kind code is the letter codes to distinguish patent documents as defined in ST.16 and Sequence identification number is the number of the sequence in that application or patent.
Example:
pat|WO|2013999999|A1|123456