Why is there no style object in the Notify Message ?

["Saha, Sayandeb" <ssaha@netplane.com>]

Hi, 
Section 4.3.1 of draft-ietf-mpls-generalized-rsvp-te-07.txt defines

<downstream notify session> ::= <SESSION> [<POLICY_DATA>...]
                                                 <flow descriptor list>

Is there any reason why the style object is missing in the above
definition??
Considering the fact that the style object is very intimately linked with
the <flow descriptor list>
and virtually defines it and is mandatory in every other message viz. Resv,
ResvTear, ResvErr
and ResvConf which have the <flow descriptor list>; Is there any specific
reason why this was 
omitted from the Notify Message ??

Regards
Sayan